TY - Generic
T1 - Feature extraction and classification for pupillary images of rats
Y1 - 2018
A1 - Kalrmár, G
A1 - Büki, A
A1 - Kekesi, G
A1 - Horváth, G
A1 - Nyúl, LG
AB - The investigation of the pupillary light reflex (PLR) is a well-known method to provide information about the functionality of the autonomic nervous system. Pupillometry, a non-invasive technique, was applied in our lab to study the schizophrenia-related PLR alterations in a new selectively bred rat substrain, named WISKET. The pupil responses to light impulses were recorded with an infrared camera; the videos were automatically processed and features were extracted. Besides the classical statistical analysis (ANOVA), feature selection and classification were applied to reveal the significant differences in the PLR parameters between the control and WISKET animals.

JF - The 11th Conference of PhD Students in Computer Science. Volume of short papers.
CY - Szeged, Hungary
UR - http://www.inf.u-szeged.hu/~cscs/pdf/cscs2018.pdf
ER -
TY - JOUR
T1 - Impaired pupillary control in “schizophrenia-like” WISKET rats. Autonomic Neuroscience: Basic and Clinical.
JF - Autonomic Neuroscience: Basic and Clinical
Y1 - 2018
A1 - Büki, A
A1 - Kalmár, G
A1 - Kekesi, G
A1 - Benedek, G
A1 - Nyúl, LG
A1 - Horváth, G
AB - Patients with schizophrenia show impairments in autonomic regulation, including pupillomotor control. The aim of this study was to explore the changes of pupillary light reflex in a new substrain (WISKET) with several schizophrenia-like alterations.

Male WISKET rats housed individually (for four weeks) and treated with ketamine (for 3 × 5 days) after weaning and naive group-housed Wistar rats (controls) were involved in the study. The pupillary light reflex was studied in two series after sedation (diazepam) or anesthesia (chloral hydrate). Video recordings were evaluated with custom made video analyzer software.

Several significant changes were observed between the two groups: the initial and minimum pupil diameters were greater, the degree of the constriction was lower, and the flatness of the curve and the total duration of constriction were shorter in the sedated WISKET rats. No other pupillary parameters (latency, amplitude and redilation) showed significant alterations.

Chloral hydrate anesthesia prolonged the constriction and redilation processes compared to the sedated animals, and diminished the differences between the groups.

In conclusion, WISKET rats showed disturbances in the pupillary light reflex, suggesting a general shift of autonomic balance towards a sympathetic predominance. The results provide further evidence to support the validity of WISKET rats as a complex, chronic animal model of schizophrenia.

PB - Elsevier
VL - 213
ER -
TY - JOUR
T1 - Image processing-based automatic pupillometry on infrared videos.
JF - Acta Cybernetica
Y1 - 2017
A1 - Kalmár, G
A1 - Büki, A
A1 - Kekesi, G
A1 - Horváth, G
A1 - Nyúl, LG
AB - Pupillometry is a non-invasive technique that can be used to objectively characterize pathophysiological changes involving the pupillary reflex. It is essentially the measurement of the pupil diameter over time. Here, specially designed computer algorithms provide fast, reliable and reproducible solutions for the analysis. These methods use a priori information about the shape and color of the pupil. Our study focuses on measuring the diameter and dynamics of the pupils of rats with schizophrenia using videos recorded with a modified digital camera under infrared (IR) illumination. We developed a novel, robust method that measures the size of a pupil even under poor circumstances (noise, blur, reflections and occlusions). We compare our results with measurements obtained using manual annotation.

PB - Szegedi Tudományegyetem / University of Szeged
CY - Szeged
VL - 23
UR - http://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/29
IS - 2
ER -
TY - JOUR
T1 - Binary image reconstruction from a small number of projections and the morphological skeleton
JF - ANNALS OF MATHEMATICS AND ARTIFICIAL INTELLIGENCE
Y1 - 2015
A1 - Norbert Hantos
A1 - Szabolcs Iván
A1 - Péter Balázs
A1 - Kálmán Palágyi
PB - Springer
VL - 75
IS - 1
ER -
TY - CHAP
T1 - Collaborative Mobile 3D Reconstruction of Urban Scenes
T2 - Proceedings of the ACCV Workshop on Intelligent Mobile and Egocentric Vision (ACCV-IMEV), Lecture Notes in Computer Science
Y1 - 2015
A1 - Attila Tanacs
A1 - András Majdik
A1 - Levente Hajder
A1 - Jozsef Molnar
A1 - Zsolt Santa
A1 - Zoltan Kato
ED - Chu-Song Chen
ED - Mohan Kankanhall
ED - Shang-Hong Lai
ED - Joo Hwee
JF - Proceedings of the ACCV Workshop on Intelligent Mobile and Egocentric Vision (ACCV-IMEV), Lecture Notes in Computer Science
PB - Springer
CY - Singapore
ER -
TY - JOUR
T1 - Discrete tomographic reconstruction via adaptive weighting of gradient descents
JF - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization
Y1 - 2015
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
AB - Discrete tomography (DT) is a set of tools for reconstructing the inner structure of objects consisting of only few different homogeneous materials. We propose a new method for multivalued DT, which performs the reconstruction as an energy minimisation task. For this algorithm, we define an energy function that can mathematically formulate the reconstruction task, and design a novel optimisation process for approximating the minima of this energy function. We validate the algorithm by comparing its performance with other cutting-edge reconstruction algorithms from the literature. We show that our method can compete with the currently used reconstruction techniques and under certain circumstances (e.g. with a low number of projections, or when the projection data are affected by random noise) it can even outperform them.

PB - Taylor&Francis
VL - 3
IS - 2
ER -
TY - CHAP
T1 - Equivalent Sequential and Parallel Subiteration-Based Surface-Thinning Algorithms
T2 - Proceedings of Combinatorial Image Analysis: 17th International Workshop, IWCIA 2015
Y1 - 2015
A1 - Kálmán Palágyi
A1 - Gábor Németh
A1 - Péter Kardos
ED - Reneta P Barneva
ED - Bhattacharya, B. B.
ED - Valentin E Brimkov
JF - Proceedings of Combinatorial Image Analysis: 17th International Workshop, IWCIA 2015
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Calcutta, India
VL - 9448
SN - 978-3-319-26144-7
JO - LNCS
ER -
TY - JOUR
T1 - Estimation of linear deformations of 2D and 3D fuzzy objects
JF - PATTERN RECOGNITION
Y1 - 2015
A1 - Attila Tanacs
A1 - Joakim Lindbald
A1 - Nataša Sladoje
A1 - Zoltan Kato
AB - Registration is a fundamental task in image processing, it is used to determine geometric correspondences between images taken at different times and/or from different viewpoints. Here we propose a general framework in *n*-dimensions to solve binary shape/object matching problems without the need of establishing additional point or other type of correspondences. The approach is based on generating and solving polynomial systems of equations. We also propose an extension which, provided that a suitable segmentation method can produce a fuzzy border representation, further increases the registration precision. Via numerous synthetic and real test we examine the different solution techniques of the polynomial systems of equations. We take into account a direct analytical, an iterative least-squares, and a combined method. Iterative and combined approaches produce the most precise results. Comparison is made against competing methods for rigid-body problems. Our method is orders of magnitude faster and is able to recover alignment regardless of the magnitude of the deformation compared to the narrow capture range of others. The applicability of the proposed methods is demonstrated on real X-ray images of hip replacement implants and 3D CT volumes of the pelvic area. Since the images must be parsed through only once, our approach is especially suitable for solving registration problems of large images.

PB - Elsevier
VL - 48
IS - 4
ER -
TY - JOUR
T1 - Fast recognition of natural feature identifiers by a mobile phone
JF - Acta Cybernetica
Y1 - 2015
A1 - Melinda Katona
A1 - László G Nyúl
PB - University of Szeged
CY - Szeged, Hungary
VL - 22
IS - 1
ER -
TY - CONF
T1 - Időskori makula degeneráció kvantitatív jellemzése SD-OCT képek automatikus elemzésével
T2 - A XXVIII. Neumann Kollokvium konferencia-kiadványa
Y1 - 2015
A1 - László Gábor Varga
A1 - Melinda Katona
A1 - Tamás Grósz
A1 - József Dombi
A1 - Attila Kovács
A1 - Rózsa Dégi
A1 - László G Nyúl
JF - A XXVIII. Neumann Kollokvium konferencia-kiadványa
PB - Neumann János Számítógép-tudományi Társaság
CY - Veszprém, Hungary
ER -
TY - JOUR
T1 - Improved QR Code Localization Using Boosted Cascade of Weak Classifiers
JF - Acta Cybernetica
Y1 - 2015
A1 - Péter Bodnár
A1 - László G Nyúl
PB - University of Szeged
CY - Szeged, Hungary
VL - 22
IS - 1
ER -
TY - CONF
T1 - Localization of Visual Codes using Fuzzy Inference System
T2 - International Conference on Computer Vision Theory and Applications (VISAPP)
Y1 - 2015
A1 - Péter Bodnár
A1 - Nyúl, László Gábor
ED - J Braz
ED - S Battiato
ED - F Imai
JF - International Conference on Computer Vision Theory and Applications (VISAPP)
PB - SciTePress
CY - Berlin, Germany
ER -
TY - JOUR
T1 - A Measure of Directional Convexity Inspired by Binary Tomography
JF - Fundamenta Informaticae
Y1 - 2015
A1 - Péter Balázs
A1 - Zoltán Ozsvár
A1 - Tamás Sámuel Tasi
A1 - László G Nyúl
AB - Inspired by binary tomography, we present a measure of directional convexity of binary images combining various properties of the configuration of 0s and 1s in the binary image. The measure can be supported by proper theory, is easy to compute, and as shown in our experiments, behaves intuitively. The measure can be useful in numerous applications of digital image processing and pattern recognition, and especially in binary tomography. We show in detail an application of this latter one, by providing a novel reconstruction algorithm for almost hv-convex binary images. We also present experimental results and mention some of the possible generalizations of the measure.

VL - 141
IS - 2-3
ER -
TY - JOUR
T1 - Periosteal microcirculatory reactions in a zoledronate-induced osteonecrosis model of the jaw in rats
JF - Clinical Oral Investigations
Y1 - 2015
A1 - Ágnes Janovszky
A1 - Andrea Szabó
A1 - Renáta Varga
A1 - Dénes Garab
A1 - Mihály Boros
A1 - Csilla Mester
A1 - Nikolett Beretka
A1 - Tamás Zombori
A1 - Hans-Peter Wiesmann
A1 - Ricardo Bernhardt
A1 - Imre Ocsovszki
A1 - Péter Balázs
A1 - József Piffkó
AB - ### Objectives

Nitrogen-containing bisphosphonates induce osteonecrosis mostly in the jaw and less frequently in other bones. Because of the crucial role of periosteal perfusion in bone repair, we investigated zoledronate-induced microcirculatory reactions in the mandibular periosteum in comparison with those in the tibia in a clinically relevant model of bisphosphonate-induced medication-related osteonecrosis of the jaw (MRONJ).

### Materials and methods

Sprague–Dawley rats were treated with zoledronate (ZOL; 80 i.v. μg/kg/week over 8 weeks) or saline vehicle. The first two right mandibular molar teeth were extracted after 3 weeks. Various systemic and local (periosteal) microcirculatory inflammatory parameters were examined by intravital videomicroscopy after 9 weeks.

### Results

Gingival healing disorders (∼100 %) and MRONJ developed in 70 % of ZOL-treated cases but not after saline (shown by micro-CT). ZOL induced significantly higher degrees of periosteal leukocyte rolling and adhesion in the mandibular postcapillary venules (at both extraction and intact sites) than at the tibia. Leukocyte NADPH-oxidase activity was reduced; leukocyte CD11b and plasma TNF-alpha levels were unchanged.

### Conclusion

Chronic ZOL treatment causes a distinct microcirculatory inflammatory reaction in the mandibular periosteum but not in the tibia. The local reaction in the absence of augmented systemic leukocyte inflammatory activity suggests that topically different, endothelium-specific changes may play a critical role in the pathogenesis of MRONJ.

### Clinical relevance

This model permits for the first time to explore the microvascular processes in the mandibular periosteum after chronic ZOL treatment. This approach may contribute to a better understanding of the pathomechanism and the development of strategies to counteract bisphosphonate-induced side effects.

PB - Springer
VL - 19
IS - 6
ER -
TY - CONF
T1 - QR kód lokalizáció kaszkádolt gyenge osztályozók használatával
T2 - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
Y1 - 2015
A1 - Péter Bodnár
A1 - László Gábor Nyúl
JF - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
CY - Kecskemét, Magyarország
ER -
TY - JOUR
T1 - Realigning 2D and 3D Object Fragments without Correspondences
JF - Pattern Analysis and Machine Intelligence, IEEE Transactions on
Y1 - 2015
A1 - Csaba Domokos
A1 - Zoltan Kato
AB - This paper addresses the problem of simultaneous estimation of different linear deformations, resulting in a global non-linear transformation, between an original object and its broken fragments. A general framework is proposed without using correspondences, where the solution of a polynomial system of equations directly provides the parameters of the alignment. We quantitatively evaluate the proposed algorithm on a large synthetic dataset containing 2D and 3D images, where linear (rigid-body and affine) transformations are considered. We also conduct an exhaustive analysis of the robustness against segmentation errors and the numerical stability of the proposed method. Moreover, we present experiments on 2D real images as well as on volumetric medical images.

PB - IEEE
VL - pp
IS - 99
ER -
TY - CONF
T1 - Semi-automatic tumor contouring method using PET and MRI medical images
T2 - Computational Vision and Medical Image Processing
Y1 - 2015
A1 - Szabolcs Urbán
A1 - László Ruskó
A1 - Antal Nagy
ED - Joao Manuel
ED - R S Tavares
ED - R M Natal Jorge
JF - Computational Vision and Medical Image Processing
PB - CRC Press - Taylor&Francis Group
CY - Tenerife, Spain
SN - 978-1-138-02926-2
ER -
TY - CONF
T1 - Topology Preserving Reductions and Additions on the Triangular, Square, and Hexagonal Grids
T2 - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
Y1 - 2015
A1 - Péter Kardos
A1 - Kálmán Palágyi
AB - The Euclidean plane can be partitioned into three kinds of

regular polygons, which results in triangular, square and hexagonal grids.

While the topology of the square grid is well-established, less emphasis

is put on the remaining two regular sampling schemes. In this paper we

summarize the results of our research that aimed to give some general

characterizations of simple pixels and sufficient conditions for topology-

preserving operators in the mentioned grids.

JF - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
CY - Kecskemét, Magyarország
ER -
TY - CONF
T1 - Topology-Preserving Equivalent Parallel and Sequential 4-Subiteration 2D Thinning Algorithms
T2 - Image and Signal Processing and Analysis (ISPA), 2015 9th International Symposium on
Y1 - 2015
A1 - Kálmán Palágyi
A1 - Gábor Németh
A1 - Péter Kardos
ED - S Loncaric
ED - D Lerski
ED - H Eskola
ED - R Bregovic
AB - Thinning is a frequently applied technique for extracting centerlines from 2D binary objects. Parallel thinning algorithms can remove a set of object points simultaneously, while sequential algorithms traverse the boundary of objects, and consider the actually visited single point for possible removal. Two thinning algorithms are called equivalent if they produce the same result for each input picture. This paper presents the very first pair of equivalent 2D sequential and parallel subiteration-based thinning algorithms. These algorithms can be implemented directly on a conventional sequential computer or on a parallel computing device. Both of them preserve topology for (8, 4) pictures sampled on the square grid.

JF - Image and Signal Processing and Analysis (ISPA), 2015 9th International Symposium on
PB - IEEE
CY - Zagreb, Croatia
SN - 978-1-4673-8032-4
ER -
TY - CONF
T1 - Újszülöttek monitorozása képfolyam elemzéssel
T2 - A XXVIII. Neumann Kollokvium konferencia-kiadványa
Y1 - 2015
A1 - Jozsef Nemeth
A1 - András Bánhalmi
A1 - László G Nyúl
A1 - Márta Fidrich
A1 - Zsolt Szkiva
A1 - Péter Franczia
A1 - Csaba Berezki
A1 - Vilmos Bilicki
JF - A XXVIII. Neumann Kollokvium konferencia-kiadványa
PB - Neumann János Számítógép-tudományi Társaság
CY - Veszprém, Hungary
SN - 978-615-5036-10-1
ER -
TY - CONF
T1 - Vékonyítás a végpont-megőrzés felülvizsgálatáva
T2 - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
Y1 - 2015
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
AB - A vékonyítás mint iteratív objektum redukció gyakran alkalmazott

vázkijelölo módszer. A legtöbb létezo vékonyító algoritmus végpontok - vagyis releváns geometriai információt hordozó objektumpontok - megorzésével biztosítja azt, hogy ne törlodjenek az objektumok alakját reprezentáló fontos részletek. Ennek a megközelítésnek hátránya, hogy számos nemkívánatos vázágat eredményezhet. Ebben a cikkben egy olyan módszert mutatunk be, amellyel jelentosen csökkentheto a hamis vázágak száma. Ráadásul az itt bemutatott megközelítés tetszoleges végpont-megorzo 2D vékonyító algoritmusban alkalmazható.

JF - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
CY - Kecskemét, Magyarország
ER -
TY - CONF
T1 - Vizuális kódok lokalizációja mély egyenirányított neurális háló használatával
T2 - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája.
Y1 - 2015
A1 - Péter Bodnár
A1 - László Gábor Nyúl
A1 - Tamás Grósz
A1 - László Tóth
JF - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája.
CY - Kecskemét, Magyarország
ER -
TY - CONF
T1 - Vonalkódok és természetes vizuális azonosítók felismerése valós időben
T2 - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
Y1 - 2015
A1 - Melinda Katona
A1 - László Gábor Nyúl
JF - Képfeldolgozók és Alakfelismerők Társaságának 10. országos konferenciája
CY - Kecskemét, Magyarország
ER -
TY - CONF
T1 - 3D Reconstruction of Planar Patches Seen by Omnidirectional Cameras
T2 - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
Y1 - 2014
A1 - Jozsef Molnar
A1 - Robert Frohlich
A1 - Chetverikov Dmitrij
A1 - Zoltan Kato
ED - Abdesselam Bouzerdoum
ED - Lei Wang
ED - Philip Ogunbona
ED - Wanqing Li
ED - Son Lam Phung
JF - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
PB - IEEE
CY - Wollongong, Australia
ER -
TY - CHAP
T1 - 3D Reconstruction of Planar Surface Patches: A Direct Solution
T2 - Proceedings of the ACCV Workshop on Big Data in 3D Computer Vision (ACCV-BigData3DCV)
Y1 - 2014
A1 - Jozsef Molnar
A1 - Rui Huang
A1 - Zoltan Kato
ED - Jian Zhang
ED - Mohammed Bennamoun
ED - Fatih Porikli
JF - Proceedings of the ACCV Workshop on Big Data in 3D Computer Vision (ACCV-BigData3DCV)
PB - Springer
CY - Singapore, Szingapúr
ER -
TY - CONF
T1 - Affine Alignment of Occluded Shapes
T2 - International Conference on Pattern Recognition (ICPR)
Y1 - 2014
A1 - Zsolt Santa
A1 - Zoltan Kato
ED - Michael Felsberg
JF - International Conference on Pattern Recognition (ICPR)
PB - IEEE
CY - Stockholm, Svédország
SN - 978-4-9906441-0-9
ER -
TY - JOUR
T1 - Application of DNA chip scanning technology for the automatic detection of Chlamydia trachomatis and Chlamydia pneumoniae inclusions.
JF - ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
Y1 - 2014
A1 - Anita Bogdanov
A1 - Valéria Endrész
A1 - Szabolcs Urbán
A1 - Ildikó Lantos
A1 - Judit Deák
A1 - Katalin Burián
A1 - K Önder
A1 - Ferhan Ayaydin
A1 - Péter Balázs
A1 - Dezső P Virók
AB - Chlamydiae are obligate intracellular bacteria that propagate in the inclusion, a specific niche inside the host cell. The standard method for counting chlamydiae is the immunofluorescent staining and manual counting of chlamydial inclusions. High or medium throughput estimation of the reduction in chlamydia inclusions should be the basis of testing antichlamydial compounds and other drugs that positively or negatively influence chlamydial growth, yet low-throughput manual counting is the common approach. To overcome the time-consuming and subjective manual counting we developed an automatic inclusion counting system based on a commercially available DNA chip scanner. Fluorescently labeled inclusions are detected by the scanner, and the image is processed by ChlamyCount, a custom plugin of the ImageJ software environment. ChlamyCount was able to measure the inclusion counts over a one log dynamic range with high correlation to the theoretical counts. ChlamyCount was capable of accurately determining the minimum inhibitory concentration of the novel antimicrobial compound PCC00213 and the already known antichlamydial antibiotics moxifloxacin and tetracycline. ChlamyCount was also able to measure the chlamydial growth altering effect of drugs that influence host-bacterium interaction such as interferon-gamma, DEAE-dextran and cycloheximide. ChlamyCount is an easily adaptable system for testing antichlamydial antimicrobials and other compounds that influence Chlamydia-host interactions.

VL - 58
SN - 0066-4804
IS - 1
N1 - UT: 000329581100051ScopusID: 84891513311doi: 10.1128/AAC.01400-13online megjelent 2013
JO - ANTIMICROB AGENTS CH
ER -
TY - JOUR
T1 - Automatikus azonosítás és hitelesítés vizuális kódokkal
JF - HIRADÁSTECHNIKA
Y1 - 2014
A1 - Melinda Katona
A1 - László Gábor Nyúl
VL - 69
IS - 1
ER -
TY - Generic
T1 - Eliminating switching components in binary matrices
Y1 - 2014
A1 - Norbert Hantos
A1 - Péter Balázs
JF - Proceedings of the 9th Conference of PhD Students in Computer Science (CSCS'14)
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CHAP
T1 - Equivalent 2D sequential and parallel thinning
T2 - Combinatorial Image Analysis
Y1 - 2014
A1 - Kálmán Palágyi
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Josef Šlapal
JF - Combinatorial Image Analysis
PB - Springer
CY - Brno, Czech Republic
ER -
TY - CONF
T1 - Establishing Correspondences between Planar Image Patches
T2 - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
Y1 - 2014
A1 - Attila Tanacs
A1 - András Majdik
A1 - Jozsef Molnar
A1 - Atul Rai
A1 - Zoltan Kato
ED - Abdesselam Bouzerdoum
ED - Lei Wang
ED - Philip Ogunbona
ED - Wanqing Li
ED - Son Lam Phung
JF - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
PB - IEEE
CY - Wollongong, Australia
ER -
TY - CHAP
T1 - Fast Heuristics for Eliminating Switching Components in Binary Matrices by 0-1 Flips
T2 - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications: 19th Iberoamerican Congress (CIARP)
Y1 - 2014
A1 - Norbert Hantos
A1 - Péter Balázs
ED - E. Bayro-Corrochano
ED - E. Hancock
AB - Switching components are special patterns in binary matrices that play an essential role in many image processing and pattern analysis tasks. Finding the minimal number of 0s that must be switched to 1s in order to eliminate all switching components is an NP-complete problem. We present two novel-type heuristics for the above problems and show via experiments that they outperform the formerly proposed ones, both in optimality and in running time.

JF - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications: 19th Iberoamerican Congress (CIARP)
T3 - LNCS
PB - Springer
CY - Puerto Vallarta, Mexico
SN - 978-3-319-12567-1
JO - LNCS
ER -
TY - Generic
T1 - Fast recognition of natural feature identifiers by a mobile phone
Y1 - 2014
A1 - Melinda Katona
A1 - László Gábor Nyúl
JF - Conference of PhD Students in Computer Science. Volume of extended abstracts
PB - Institute of Informatics, University of Szeged
CY - Szeged
ER -
TY - CHAP
T1 - Képfeldolgozás a szegedi informatikus-képzésben
T2 - Informatika a felsőoktatásban 2014
Y1 - 2014
A1 - Péter Balázs
A1 - Endre Katona
A1 - Zoltan Kato
A1 - Antal Nagy
A1 - Gábor Németh
A1 - László Gábor Nyúl
A1 - Kálmán Palágyi
A1 - Attila Tanacs
A1 - László Gábor Varga
ED - Roland Kunkli
ED - Ildikó Papp
ED - Edéné Rutkovszky
JF - Informatika a felsőoktatásban 2014
PB - University of Debrecen
CY - Debrecen, Hungary
ER -
TY - JOUR
T1 - Local and global uncertainty in binary tomographic reconstruction
JF - COMPUTER VISION AND IMAGE UNDERSTANDING
Y1 - 2014
A1 - László Gábor Varga
A1 - László Gábor Nyúl
A1 - Antal Nagy
A1 - Péter Balázs
AB - In binary tomography the goal is to reconstruct the innerstructure of homogeneous objects from their projections. This is usually required from a low number of projections, which are also likely to be aﬀected by noise and measurement errors. In general, the distorted and incomplete projection data holds insuﬃcient information for the correct reconstruction of the original object. In this paper, we describe two methods for approximating the local uncertainty of the reconstructions, i.e., identifying how the information stored in the projections determine each part of the reconstructed image. These methods can measure the uncertainty of the reconstruction without any knowledge from the original object itself. Moreover, we provide a global uncertainty measure that can assess the information content of a projection set and predict the error to be expected in the reconstruction of a homogeneous object. We also give an experimental evaluation of our proposed methods, mention some of their possible applications, and describe how the uncertainty measure can be used to improve the performance of the DART reconstruction algorithm.

SN - 1077-3142
N1 - Art. No.: S1077-3142(14)00117-9doi: 10.1016/j.cviu.2014.05.006Article in Press
JO - COMPUT VIS IMAGE UND
ER -
TY - CHAP
T1 - Localization of Visual Codes in the DCT Domain Using Deep Rectier Neural Networks
T2 - International Conference on Informatics in Control, Automation and Robotics (ICINCO)
Y1 - 2014
A1 - Péter Bodnár
A1 - Tamás Grósz
A1 - László Tóth
A1 - László Gábor Nyúl
ED - Joaquim Filipe
ED - Oleg Gusikhin
ED - Kurosh Madani
ED - Jurek Sasiadek
JF - International Conference on Informatics in Control, Automation and Robotics (ICINCO)
PB - SCITEPRESS
CY - Setúbal
N1 - Art. No.: 6Közlésre elfogadva
ER -
TY - CHAP
T1 - Orvosi képfeldolgozás az SZTE Képfeldolgozás és Számítógépes Grafika Tanszéken
T2 - Orvosi Informatika 2014: A XXVII. Neumann Kollokvium konferencia-kiadványa
Y1 - 2014
A1 - László Gábor Nyúl
JF - Orvosi Informatika 2014: A XXVII. Neumann Kollokvium konferencia-kiadványa
PB - Pannon Egyetem, Veszprém
CY - Szeged, Hungary
SN - 978-963-396-040-0
ER -
TY - CHAP
T1 - QR Code Localization Using Boosted Cascade of Weak Classifiers
T2 - Image Analysis and Recognition (ICIAR)
Y1 - 2014
A1 - Péter Bodnár
A1 - László Gábor Nyúl
ED - Mohamed Kamel
ED - Aurélio Campilho
AB - Usage of computer-readable visual codes became common in oureveryday life at industrial environments and private use. The reading process of visual codes consists of two steps: localization and data decoding. Unsupervised localization is desirable at industrial setups and for visually impaired people. This paper examines localization efficiency of cascade classifiers using Haar-like features, Local Binary Patterns and Histograms of Oriented Gradients, trained for the finder patterns of QR codes and for the whole code region as well, and proposes improvements in post-processing.

JF - Image Analysis and Recognition (ICIAR)
T3 - Lecture Notes In Computer Science
PB - Springer-Verlag
CY - Vilamura, Portugal
N1 - Art. No.: 225Accepted for publication
ER -
TY - Generic
T1 - QR Code Localization Using Boosted Cascade of Weak Classifiers
Y1 - 2014
A1 - Péter Bodnár
A1 - László Gábor Nyúl
JF - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
PB - Institute of Informatics, University of Szeged
CY - Szeged
ER -
TY - CHAP
T1 - QR code localization using deep neural networks
T2 - International Workshop on Machine Learning for Signal Processing
Y1 - 2014
A1 - Tamás Grósz
A1 - Péter Bodnár
A1 - László Tóth
A1 - László Gábor Nyúl
ED - Mboup Mamadou
ED - Adali Tülay
ED - Eric Moreau
ED - Jan Larsen
ED - Kevin Guelton
JF - International Workshop on Machine Learning for Signal Processing
PB - IEEE
CY - Sep 2014, Reims, France
N1 - Art. No.: 43Accepted for publication#Könyv Kiadás helye ismeretlen
ER -
TY - Generic
T1 - Reconstruction of hv-convex binary matrices from horizontal and vertical projections based on simulated annealing
Y1 - 2014
A1 - Zoltán Ozsvár
A1 - Péter Balázs
JF - Proceedings of the 9th Conference of PhD Students in Computer Science (CSCS'14)
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CHAP
T1 - Smoothing Filters in the DART Algorithm
T2 - Combinatorial Image Analysis
Y1 - 2014
A1 - Antal Nagy
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Josef Šlapal
JF - Combinatorial Image Analysis
PB - Springer
CY - May 2014, Brno, Czech Republic
UR - http://link.springer.com/chapter/10.1007%2F978-3-319-07148-0_20
ER -
TY - CHAP
T1 - Sufficient conditions for general 2D operators to preserve topology
T2 - Combinatorial Image Analysis
Y1 - 2014
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Josef Šlapal
AB - An important requirement for various applications of binary image processing is to preserve topology. This issue has been earlier studied for two special types of image operators, namely, reductions and additions, and there have been some sufficient conditions proposed for them. In this paper, as an extension of those earlier results, we give novel sufficient criteria for general operators working on 2D pictures.

JF - Combinatorial Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer
CY - May 2014, Brno, Czech Republic
VL - 8466
SN - 978-3-319-07147-3
UR - http://dx.doi.org/10.1007/978-3-319-07148-0_10
JO - Conference Paper
ER -
TY - CONF
T1 - SZTE-NLP: Clinical Text Analysis with Named Entity Recognition
T2 - The 8th International Workshop on Semantic Evaluation (SemEval 2014)
Y1 - 2014
A1 - Melinda Katona
A1 - Richárd Farkas
ED - Preslav Nakov
ED - Torsten Zesch
JF - The 8th International Workshop on Semantic Evaluation (SemEval 2014)
PB - ACL
CY - Dublin, Ireland
SN - 978-1-941643-24-2
ER -
TY - CHAP
T1 - Wlab of University of Szeged at ImageCLEF 2014 Plant Identification Task
T2 - CLEF2014 Working Notes: Working Notes for CLEF 2014 Conference
Y1 - 2014
A1 - András Bánhalmi
A1 - Dénes Paczolay
A1 - Vilmos Bilicki
A1 - László Gábor Nyúl
A1 - Árpád Sárosi
ED - Linda Cappellato
ED - Nicola Ferro
ED - Martin Halvey
ED - Wessel Kraai
JF - CLEF2014 Working Notes: Working Notes for CLEF 2014 Conference
PB - CEUR-WS
CY - Sheffield, UK
VL - 1180
ER -
TY - Generic
T1 - X. Magyar Számítógépes Nyelvészeti Konferencia
Y1 - 2014
ED - Attila Tanacs
ED - Viktor Varga
ED - Veronika Vincze
PB - Szegedi Tudományegyetem Informatikai Tanszékcsoport
CY - Szeged
UR - http://www.inf.u-szeged.hu/rgai/mszny2014/
ER -
TY - CONF
T1 - 2D és 3D bináris objektumok lineáris deformáció-becslésének numerikus megoldási lehetőségei
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Attila Tanacs
A1 - Joakim Lindblad
A1 - Nataša Sladoje
A1 - Zoltan Kato
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - JOUR
T1 - Barcode detection using local analysis, mathematical morphology, and clustering
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2013
A1 - Péter Bodnár
A1 - László Gábor Nyúl
AB - Barcode detection is required in a wide range of real-lifeapplications. Imaging conditions and techniques vary considerably and each application has its own requirements for detection speed and accuracy. In our earlier works we built barcode detectors using morphological operations and uniform partitioning with several approaches and showed their behaviour on a set of test images. In this work, we extend those ideas with clustering, contrast measuring, distance transformation and probabilistic Hough transformation.

VL - 21
SN - 0324-721X
IS - 1
JO - ACTA CYBERN-SZEGED
ER -
TY - CONF
T1 - Barcode detection with uniform partitioning and distance transformation
T2 - IASTED International Conference on Computer Graphics and Imaging (CGIM)
Y1 - 2013
A1 - Péter Bodnár
A1 - László Gábor Nyúl
ED - L Linsen
AB - Barcode detection is required in a wide range of real-lifeapplications. Imaging conditions and techniques vary considerably and each application has its own requirements for detection speed and accuracy. In our earlier works we used uniform partitioning with several approaches for detection of various types of 1D and 2D barcodes and showed their behaviour on a set of test images. In this work, we extend the partitioning idea and replace scan-line based methods with distance transformation to improve accuracy.

JF - IASTED International Conference on Computer Graphics and Imaging (CGIM)
PB - IASTED - Acta Press
CY - Innsbruck, Austria
UR - http://www.actapress.com/PaperInfo.aspx?paperId=454988
N1 - doi: 10.2316/P.2013.797-022
ER -
TY - CONF
T1 - A comparison of heuristics for reconstructing hv-convex binary matrices from horizontal and vertical projections
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Zoltán Ozsvár
A1 - Péter Balázs
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - JOUR
T1 - Complexity results for reconstructing binary images with disjoint components from horizontal and vertical projections
JF - DISCRETE APPLIED MATHEMATICS
Y1 - 2013
A1 - Péter Balázs
VL - 161
SN - 0166-218X
N1 - UT: 000322689900002ScopusID: 84874628675doi: 10.1016/j.dam.2013.02.004
JO - DISCRETE APPL MATH
ER -
TY - JOUR
T1 - Conference of PhD Students in Computer Science
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2013
A1 - Kálmán Palágyi
VL - 21
SN - 0324-721X
IS - 1
JO - ACTA CYBERN-SZEGED
ER -
TY - CONF
T1 - Correspondence-less non-rigid registration of triangular surface meshes
T2 - IEEE Conference on Computer Vision and Pattern Recognition (CVPR)
Y1 - 2013
A1 - Zsolt Santa
A1 - Zoltan Kato
AB - A novel correspondence-less approach is proposed to find a thin plate spline map between a pair of deformable 3D objects represented by triangular surface meshes. The proposed method works without landmark extraction and feature correspondences. The aligning transformation is found simply by solving a system of nonlinear equations. Each equation is generated by integrating a nonlinear function over the object's domains. We derive recursive formulas for the efficient computation of these integrals. Based on a series of comparative tests on a large synthetic dataset, our triangular mesh-based algorithm outperforms state of the art methods both in terms of computing time and accuracy. The applicability of the proposed approach has been demonstrated on the registration of 3D lung CT volumes. © 2013 IEEE.

JF - IEEE Conference on Computer Vision and Pattern Recognition (CVPR)
PB - IEEE
CY - Portland, OR, USA
N1 - ScopusID: 84887348013doi: 10.1109/CVPR.2013.295
ER -
TY - CHAP
T1 - Deletion Rules for Equivalent Sequential and Parallel Reductions
T2 - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications
Y1 - 2013
A1 - Kálmán Palágyi
ED - Jose Ruiz-Shulcloper
ED - Gabriella Sanniti di Baja
AB - A reduction operator transforms a binary picture only by changing some black points to white ones, which is referred to as deletion. Sequential reductions may delete just one point at a time, while parallel reductions can alter a set of points simultaneously. Two reductions are called equivalent if they produce the same result for each input picture. This work lays a bridge between the parallel and the sequential strategies. A class of deletion rules are proposed that provide 2D parallel reductions being equivalent to sequential reductions. Some new sufficient conditions for topology-preserving parallel reductions are also reported.

JF - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Berlin; Heidelberg
SN - 978-3-642-41821-1
UR - http://link.springer.com/chapter/10.1007%2F978-3-642-41822-8_3
N1 - Lecture Notes in Computer Science, Vol. 8258
JO - Conference Paper
ER -
TY - CHAP
T1 - Directional Convexity Measure for Binary Tomography
T2 - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications
Y1 - 2013
A1 - Tamás Sámuel Tasi
A1 - László Gábor Nyúl
A1 - Péter Balázs
ED - Gabriella Sanniti di Baja
ED - Jose Ruiz-Shulcloper
AB - There is an increasing demand for a new measure of convexity fordiscrete sets for various applications. For example, the well- known measures for h-, v-, and hv-convexity of discrete sets in binary tomography pose rigorous criteria to be satisfied. Currently, there is no commonly accepted, unified view on what type of discrete sets should be considered nearly hv-convex, or to what extent a given discrete set can be considered convex, in case it does not satisfy the strict conditions. We propose a novel directional convexity measure for discrete sets based on various properties of the configuration of 0s and 1s in the set. It can be supported by proper theory, is easy to compute, and according to our experiments, it behaves intuitively. We expect it to become a useful alternative to other convexity measures in situations where the classical definitions cannot be used.

JF - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications
PB - Springer Verlag
CY - Berlin; Heidelberg
UR - http://link.springer.com/chapter/10.1007%2F978-3-642-41827-3_2
N1 - ScopusID: 84893169866doi: 10.1007/978-3-642-41827-3_2
ER -
TY - JOUR
T1 - Dynamic angle selection in binary tomography
JF - COMPUTER VISION AND IMAGE UNDERSTANDING
Y1 - 2013
A1 - Joost K Batenburg
A1 - Willem Jan Palenstijn
A1 - Péter Balázs
A1 - Jan Sijbers
AB - In this paper, we present an algorithm for the dynamic selection of projection angles in binary tomography. Based on the information present in projections that have already been measured, a new projection angle is computed, which aims to maximize the information gained by adding this projection to the set of measurements. The optimization model used for angle selection is based on a characterization of solutions of the binary reconstruction problem, and a related definition of information gain. From this formal model, an algorithm is obtained by several approximation steps. Results from a series of simulation experiments demonstrate that the proposed angle selection scheme is indeed capable of finding angles for which the reconstructed image is much more accurate than for the standard angle selection scheme. © 2012 Elsevier Inc. All rights reserved.

VL - 117
SN - 1077-3142
IS - 4
N1 - UT: 000315556800002ScopusID: 84871533054doi: 10.1016/j.cviu.2012.07.005
JO - COMPUT VIS IMAGE UND
ER -
TY - CHAP
T1 - Efficient 1D and 2D barcode detection using mathematical morphology
T2 - Mathematical Morphology and Its Applications to Signal and Image Processing
Y1 - 2013
A1 - Melinda Katona
A1 - László Gábor Nyúl
ED - Chris L Luengo
ED - Gunilla Borgefors
ED - Robin Strand
AB - Barcode technology is essential in automatic identification,and is used in a wide range of real-time applications. Different code types and applications impose special problems, so there is a continuous need for solutions with improved performance. Several methods exist for code localization, that are well characterized by accuracy and speed. Particularly, high-speed processing places need reliable automatic barcode localization, e.g. conveyor belts and automated production, where missed detections cause loss of profit. Our goal is to detect automatically, rapidly and accurately the barcode location with the help of extracted image features. We propose a new algorithm variant, that outperforms in both accuracy and efficiency other detectors found in the literature using similar ideas, and also improves on the detection performance in detecting 2D codes compared to our previous algorithm.

JF - Mathematical Morphology and Its Applications to Signal and Image Processing
PB - Springer-Verlag
CY - Berlin; Heidelberg
N1 - doi: 10.1007/978-3-642-38294-9_39
ER -
TY - CHAP
T1 - Elastic Registration of 3D Deformable Objects
T2 - Proceedings of International Conference on Digital Image Computing: Techniques and Applications (DICTA)
Y1 - 2013
A1 - Zsolt Santa
A1 - Zoltan Kato
ED - Geoff West
ED - Péter Kövesi
AB - A novel correspondence-less approach is proposed to find a non-linear aligning transformation between a pair of deformable 3D objects. Herein, we consider a polynomial deformation model, but our framework can be easily adapted to other common deformations. The basic idea of the proposed method is to set up a system of nonlinear equations whose solution directly provides the parameters of the aligning transformation. Each equation is generated by integrating a nonlinear function over the object's domains. Thus the number of equations is determined by the number of adopted nonlinear functions yielding a flexible mechanism to generate sufficiently many equations. While classical approaches would establish correspondences between the shapes, our method works without landmarks. The efficiency of the proposed approach has been demonstrated on a large synthetic dataset as well as in the context of medical image registration.

JF - Proceedings of International Conference on Digital Image Computing: Techniques and Applications (DICTA)
PB - IEEE
CY - New York
UR - http://www.inf.u-szeged.hu/~kato/papers/dicta2012.pdf
N1 - UT: 000316318400010doi: 10.1109/DICTA.2012.6411674
ER -
TY - JOUR
T1 - An empirical study of reconstructing hv-convex binary matrices from horizontal and vertical projections
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2013
A1 - Zoltán Ozsvár
A1 - Péter Balázs
AB - The reconstruction of hv-convex binary matrices (or equivalently, binary images) from their horizontal and vertical projections is proved to be NP-hard. In this paper we take a closer look at the difficulty of the problem. We investigate different heuristic reconstruction algorithms of the class, and compare them from the viewpoint of running-time and reconstruction quality. Using a large set of test images of different sizes and with varying number of components, we show that the reconstruction quality can depend not only on the size of the image, but on the number and location of its components, too. We also reveal that the reconstruction time can also be affected by the number of the so-called switching components present in the image.

VL - 21
SN - 0324-721X
JO - ACTA CYBERN-SZEGED
ER -
TY - CHAP
T1 - Evaluation of Point Matching Methods for Wide-baseline Stereo Correspondence on Mobile Platforms
T2 - Proceedings of the International Symposium on Image and Signal Processing and Analysis (ISPA)
Y1 - 2013
A1 - Endre Juhász
A1 - Attila Tanacs
A1 - Zoltan Kato
ED - Giovanni Ramponi
ED - Sven Lončarić
ED - Alberto Carini
ED - Karen Egiazarian
AB - Wide-baseline stereo matching is a common problem of computer vision. By the explosion of smartphones equipped with camera modules, many classical computer vision solutions have been adapted to such platforms. Considering the widespread use of various networking options for mobile phones, one can consider a set of smart phones as an ad-hoc camera network, where each camera is equipped with a more and more powerful computing engine in addition to a limited bandwidth communication with other devices. Therefore the performance of classical vision algorithms in a collaborative mobile environment is of particular interest. In such a scenario we expect that the images are taken almost simultaneously but from different viewpoints, implying that the camera poses are significantly different but lighting conditions are the same. In this work, we provide quantitative comparison of the most important keypoint detectors and descriptors in the context of wide baseline stereo matching. We found that for resolution of 2 megapixels images the current mobile hardware is capable of providing results efficiently.

JF - Proceedings of the International Symposium on Image and Signal Processing and Analysis (ISPA)
PB - IEEE
CY - Trieste
ER -
TY - CONF
T1 - Gépkocsi felismerés elölnézeti képek alapján
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Viktor Varjas
A1 - Attila Tanacs
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - CONF
T1 - Gradiens módszerek automatikus súlyozásán alapuló diszkrét tomográfiai eljárás
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - CONF
T1 - Háromszöghálók nemlineáris illesztése megfeleltetések nélkül
T2 - Képfeldolgozók és Alakfelismerők IX. Konferenciája
Y1 - 2013
A1 - Sánta Zsolt
A1 - Kató Zoltán
JF - Képfeldolgozók és Alakfelismerők IX. Konferenciája
ER -
TY - CONF
T1 - Improved 1D and 2D barcode detection with morphological operations
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Melinda Katona
A1 - László Gábor Nyúl
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - CHAP
T1 - Linear and nonlinear shape alignment without correspondences
T2 - Proceedings of International Joint Conference on Computer Vision, Imaging and Computer Graphics - Theory and Applications (Revised Selected Papers)
Y1 - 2013
A1 - Zoltan Kato
ED - Paul Richard
ED - Gabriela Csurka
AB - We consider the estimation of diffeomorphic deformations aligning a known binary shape and its distorted observation. The classical solution consists in extracting landmarks, establishing correspondences and then the aligning transformation is obtained via a complex optimization procedure. Herein we present an alternative solution which works without landmark correspondences, is independent of the magnitude of transformation, easy to implement, and has a linear time complexity. The proposed universal framework is capable of recovering linear as well as nonlinear deformations.

JF - Proceedings of International Joint Conference on Computer Vision, Imaging and Computer Graphics - Theory and Applications (Revised Selected Papers)
T3 - Communications in Computer and Information Science
PB - Springer Verlag
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
UR - http://www.inf.u-szeged.hu/~kato/papers/visapp2012.pdf
ER -
TY - CHAP
T1 - Local uncertainty in binary tomographic reconstruction
T2 - Proceedings of the IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA 2013)
Y1 - 2013
A1 - László Gábor Varga
A1 - László Gábor Nyúl
A1 - Antal Nagy
A1 - Péter Balázs
ED - Martin Kampel
AB - We describe a new approach for the uncertainty problem arisingin the field of discrete tomography, when the low number of projections does not hold enough information for an accurate, and reliable reconstruction. In this case the lack of information results in uncertain parts on the reconstructed image which are not determined by the projections and cannot be reliably reconstructed without additional information. We provide a method that can approximate this local uncertainty of reconstructions, and show how each pixel of the reconstructed image is determined by a set of given projections. We also give experimental results for validating our approach.

JF - Proceedings of the IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA 2013)
PB - IASTED - Acta Press
CY - Calgary
N1 - ScopusID: 84876584488doi: 10.2316/P.2013.798-067
ER -
TY - CHAP
T1 - A Novel Method for Barcode Localization in Image Domain
T2 - Image Analysis and Recognition (ICIAR)
Y1 - 2013
A1 - Péter Bodnár
A1 - László Gábor Nyúl
ED - Mohamed Kamel
ED - Aurélio Campilho
AB - Barcode localization is an essential step of the barcode readingprocess. For industrial environments, having high-resolution cameras and eventful scenarios, fast and reliable localization is crucial. Images acquired in those setups have limited parameters, however, they vary at each application. In earlier works we have already presented various barcode features to track for localization process. In this paper, we present a novel approach for fast barcode localization using a limited set of pixels in image domain.

JF - Image Analysis and Recognition (ICIAR)
T3 - Lecture Notes in Computer Science
PB - Springer-Verlag
CY - Berlin
N1 - doi: 10.1007/978-3-642-39094-4_22
ER -
TY - CHAP
T1 - Parallel 3D 12-Subiteration Thinning Algorithms Based on Isthmuses
T2 - Advances in Visual Computing
Y1 - 2013
A1 - Kálmán Palágyi
ED - George Bebis
AB - Thinning is an iterative object reduction to obtain skeleton-like shape features of volumetric binary objects. Conventional thinning algorithms preserve endpoints to provide important geometric information relative to the object to be represented. An alternative strategy is also proposed that accumulates isthmuses (i.e., generalization of curve and surface interior points as skeletal elements). This paper presents two parallel isthmus-based 3D thinning algorithms that are capable of producing centerlines and medial surfaces. The strategy which is used is called subiteration-based or directional: each iteration step is composed of 12 subiterations each of which are executed in parallel. The proposed algorithms make efficient implementation possible and their topological correctness is guaranteed.

JF - Advances in Visual Computing
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Heidelberg; New York
N1 - Lecture Notes in Computer Science, Vol. 8033
ER -
TY - CONF
T1 - Parallel Thinning Based on Isthmuses
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - CHAP
T1 - Parallel Thinning on the Triangular Grid
T2 - International Conference on Cognitive Infocommunications (CogInfoCom)
Y1 - 2013
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Péter Baranyi
AB - One of the fundamental issues of human and computational cognitive psychology is pattern or shape recognition. Various applications in image processing and computer vision rely on skeleton-like shape features A possible technique for extracting these feautures is thinning. Although the majority of 2D thinning algorithms work on digital pictures sampled onthe conventional square grid, the role of some non-conventional grids, like the hexagonal and triangular grid, are of increasing importance as well. In this paper we propose numerous topolgy preserving parallel thinning algorithms that work on the triangular grid.

JF - International Conference on Cognitive Infocommunications (CogInfoCom)
PB - IEEE
CY - Budapest
SN - 978-1-4799-1543-9
ER -
TY - CHAP
T1 - Pose Estimation of Ad-hoc Mobile Camera Networks
T2 - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
Y1 - 2013
A1 - Zsolt Santa
A1 - Zoltan Kato
ED - Paulo de Souza
ED - Ulrich Engelke
ED - Ashfaqur Rahman
AB - An algorithm is proposed for the pose estimation of ad-hoc mobile camera networks with overlapping views. The main challenge is to estimate camera parameters with respect to the 3D scene without any specific calibration pattern, hence allowing for a consistent, camera-independent world coordinate system. The only assumption about the scene is that it contains a planar surface patch of a low-rank texture, which is visible in at least two cameras. Such low-rank patterns are quite common in urban environments. The proposed algorithm consists of three main steps: relative pose estimation of the cameras within the network, followed by the localization of the network within the 3D scene using a low-rank surface patch, and finally the estimation of a consistent scale for the whole system. The algorithm follows a distributed architecture, hence the computing power of the participating mobile devices are efficiently used. The performance and robustness of the proposed algorithm have been analyzed on both synthetic and real data. Experimental results confirmed the relevance and applicability of the method.

JF - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
PB - IEEE
CY - Hobart, TAS
ER -
TY - THES
T1 - Prior Information, Machine Learning, and Direction Dependency in Binary Tomography
T2 - Institute of Informatics
Y1 - 2013
A1 - Péter Balázs
JF - Institute of Informatics
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CHAP
T1 - Reconstruction and Enumeration of hv-Convex Polyominoes with Given Horizontal Projection
T2 - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications (CIARP)
Y1 - 2013
A1 - Norbert Hantos
A1 - Péter Balázs
ED - Jose Ruiz-Shulcloper
ED - Gabriella Sanniti di Baja
JF - Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications (CIARP)
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Heidelberg; London; New York
SN - 978-3-642-41821-1
N1 - ScopusID: 84893181366doi: 10.1007/978-3-642-41822-8_13
ER -
TY - JOUR
T1 - The reconstruction of polyominoes from horizontal and vertical projections and morphological skeleton is NP-complete
JF - FUNDAMENTA INFORMATICAE
Y1 - 2013
A1 - Norbert Hantos
A1 - Péter Balázs
VL - 125
SN - 0169-2968
IS - 3-4
N1 - UT: 000322028300009ScopusID: 84881495517doi: 10.3233/FI-2013-868
JO - FUND INFOR
ER -
TY - CHAP
T1 - Restoration of blurred binary images using discrete tomography
T2 - Advanced Concepts for Intelligent Vision Systems (ACIVS)
Y1 - 2013
A1 - Jozsef Nemeth
A1 - Péter Balázs
ED - Jacques Blanc-Talon
ED - Andrzej Kasinski
ED - Wilfried Philips
ED - Dan Popescu
ED - Paul Scheunders
AB - Enhancement of degraded images of binary shapes is an important task in many image processing applications, *e.g.* to provide appropriate image quality for optical character recognition. Although many image restoration methods can be found in the literature, most of them are developed for grayscale images. In this paper we propose a novel binary image restoration algorithm. As a first step, it restores the projections of the shape using 1-dimensional deconvolution, then reconstructs the image from these projections using a discrete tomography technique. The method does not require any parameter setting or prior knowledge like an estimation of the signal-to-noise ratio. Numerical experiments on a synthetic dataset show that the proposed algorithm is robust to the level of the noise. The efficiency of the method has also been demonstrated on real out-of-focus alphanumeric images.

JF - Advanced Concepts for Intelligent Vision Systems (ACIVS)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
SN - 978-3-319-02894-1
N1 - ScopusID: 84890864720doi: 10.1007/978-3-319-02895-8_8
JO - LNCS
ER -
TY - JOUR
T1 - Spectrum Skeletonization: A New Method for Acoustic Signal Feature Extraction.
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2013
A1 - Tibor Dobján
A1 - Gábor Németh
AB - Vibration Analysis Tests (VAT) and Acoustic Emission tests (AE) are used in several industrial applications. Many of them perform analysis in the frequency domain. Peaks in the power density spectrum hold relevant information about acoustic events. In this paper we propose a novel method for feature extraction of vibration samples by analyzing the shape of their auto power spectrum density function. The approach uses skeletonization techniques in order to find the hierarchical structure of the spectral peaks. The proposed method can be applied as a preprocessing step for spectrum analysis of vibration signals. ` `

PB - University of Szeged, Institute of Informatics
CY - Szeged
VL - 21
SN - 0324-721X
N1 - #Szerző vagy Forráskiadás készítője vagy Kritikai kiadás készítője ismeretlen
JO - ACTA CYBERN-SZEGED
ER -
TY - CHAP
T1 - Sufficient Conditions for Topology Preserving Additions and General Operators
T2 - Proceedings of the IASTED International Conference on Computer Graphics and Imaging (CGIM)
Y1 - 2013
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - L Linsen
AB - Topology preservation is a crucial issue of digital topology. Various applications of binary image processing rest on topology preserving operators. Earlier studies in this topic mainly concerned with reductions (i.e., operators that only delete some object points from binary images), as they form the basis for thinning algorithms. However, additions (i.e., operators that never change object points) also play important role for the purpose of generating discrete Voronoi diagrams or skeletons by influence zones (SKIZ). Furthermore, the use of general operators that may both add and delete some points to and from objects in pictures are suitable for contour smoothing. Therefore, in this paper we present some new sufficient conditions for topology preserving reductions, additions, and general operators. Two additions for 2D and 3D contour smoothing are also reported.

JF - Proceedings of the IASTED International Conference on Computer Graphics and Imaging (CGIM)
PB - IASTED - Acta Press
CY - Calgary
ER -
TY - CHAP
T1 - Targetless Calibration of a Lidar - Perspective Camera Pair
T2 - Proceedings of ICCV Workshop on Big Data in 3D Computer Vision
Y1 - 2013
A1 - Tamás Levente
A1 - Zoltan Kato
ED - Jian Zhang
ED - Mohammed Bennamoun
ED - Dan Schonfeld
ED - Zhengyou Zhang
AB - A novel method is proposed for the calibration of a camera - 3D lidar pair without the use of any special calibration pattern or point correspondences. The proposed method has no specific assumption about the data source: plain depth information is expected from the lidar scan and a simple perspective camera is used for the 2D images. The calibration is solved as a 2D-3D registration problem using a minimum of one (for extrinsic) or two (for intrinsic-extrinsic) planar regions visible in both cameras. The registration is then traced back to the solution of a non-linear system of equations which directly provides the calibration parameters between the bases of the two sensors. The method has been tested on a large set of synthetic lidar-camera image pairs as well as on real data acquired in outdoor environment.

JF - Proceedings of ICCV Workshop on Big Data in 3D Computer Vision
PB - IEEE
CY - Sydney, NSW
N1 - doi: 10.1109/ICCVW.2013.92
ER -
TY - CHAP
T1 - On Topology Preservation in Triangular, Square, and Hexagonal Grids
T2 - Proceedings of International Symposium on Image and Signal Processing and Analysis (ISPA)
Y1 - 2013
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Giovanni Ramponi
ED - Sven Lončarić
ED - Alberto Carini
ED - Karen Egiazarian
AB - There are three possible partitionings of the continuous plane into regular polygons that leads to triangular, square, and hexagonal grids. The topology of the square grid is fairly well-understood, but it cannot be said of the remaining two regular sampling schemes. This paper presents a general characterization of simple pixels and some simplified sufficient conditions for topology-preserving operators in all the three types of regular grids.

JF - Proceedings of International Symposium on Image and Signal Processing and Analysis (ISPA)
PB - IEEE
CY - Trieste
ER -
TY - CONF
T1 - Topology preserving parallel thinning on hexagonal grids
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - JOUR
T1 - Topology-preserving hexagonal thinning
JF - INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS
Y1 - 2013
A1 - Péter Kardos
A1 - Kálmán Palágyi
AB - Thinning is a well-known technique for producing skeleton-like shape features from digital binary objects in a topology-preserving way. Most of the existing thinning algorithms work on input images that are sampled on orthogonal grids; however, it is also possible to perform thinning on hexagonal grids (or triangular lattices). In this paper, we point out to the main similarities and differences between the topological properties of these two types of sampling schemes. We give various characterizations of simple points and present some new sufficient conditions for topology-preserving reductions working on hexagonal grids.

PB - Taylor & Francis
VL - 90
SN - 0020-7160
UR - http://www.tandfonline.com/doi/abs/10.1080/00207160.2012.724198#preview
IS - 8
N1 - doi: 10.1080/00207160.2012.724198
JO - INT J COMPUT MATH
ER -
TY - CHAP
T1 - A unifying framework for correspondence-less shape alignment and its medical applications
T2 - Intelligent Interactive Technologies and Multimedia
Y1 - 2013
A1 - Zoltan Kato
AB - We give an overview of our general framework for registering 2D and 3D objects without correspondences. Classical solutions consist in extracting landmarks, establishing correspondences and then the aligning transformation is obtained via a complex optimization procedure. In contrast, our framework works without landmark correspondences, is independent of the magnitude of transformation, easy to implement, and has a linear time complexity. The efficiency and robustness of the method has been demonstarted using various deformations models. Herein, we will focus on medical applications. © 2013 Springer-Verlag.

JF - Intelligent Interactive Technologies and Multimedia
T3 - Communications in Computer and Information Science
PB - Springer
CY - Allahabad, India
VL - 276 CCIS
SN - 1865-0929
N1 - ScopusID: 84875170012doi: 10.1007/978-3-642-37463-0_4T3 2nd International Conference on Intelligent Interactive Technologies and Multimedia, IITM 2013Y2 9 March 2013 through 11 March 2013
CY Allahabad
JO - COMMUN COMPUT INFORM SCI
ER -
TY - CONF
T1 - A uniqueness result for reconstructing hv-convex polyominoes from horizontal and vertical projections and morphological skeleton
T2 - Proceedings of International Symposium on Image and Signal Processing and Analysis (ISPA)
Y1 - 2013
A1 - Norbert Hantos
A1 - Péter Balázs
ED - Giovanni Ramponi
ED - Sven Lončarić
ED - Alberto Carini
ED - Karen Egiazarian
AB - In this article we study the uniqueness of the reconstruction in a special class of 4-connected hv-convex images, using two projections and the so-called morphological skeleton. Generally, if just the two projections are given, there can be exponentially many hv-convex 4-connected images satisfying them. Knowing the morphological skeleton in addition, we can reduce the number of solutions. In the studied class, the images are defined by two parameters. We show that the uniqueness of their reconstruction depends only on the values of those parameters.

JF - Proceedings of International Symposium on Image and Signal Processing and Analysis (ISPA)
PB - IEEE
CY - Trieste
ER -
TY - CONF
T1 - Vizuális kódok lokalizálásának javítása egyszerű jellemzők kombinációjával
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
Y1 - 2013
A1 - Péter Bodnár
A1 - László Gábor Nyúl
ED - László Czúni
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2013
PB - NJSZT-KÉPAF
CY - Veszprém
ER -
TY - CHAP
T1 - 3D Parallel Thinning Algorithms Based on Isthmuses
T2 - Advanced Concepts for Intelligent Vision Systems (ACIVS)
Y1 - 2012
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - Jacques Blanc-Talon
ED - Wilfried Philips
ED - Dan Popescu
ED - Paul Scheunders
ED - Pavel Zemčík
AB - Thinning is a widely used technique to obtain skeleton-like shape features (i.e., centerlines and medial surfaces) from digital binary objects. Conventional thinning algorithms preserve endpoints to provide important geometric information relative to the object to be represented. An alternative strategy is also proposed that preserves isthmuses (i.e., generalization of curve/surface interior points). In this paper we present ten 3D parallel isthmus-based thinning algorithm variants that are derived from some sufficient conditions for topology preserving reductions. ` `

JF - Advanced Concepts for Intelligent Vision Systems (ACIVS)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Brno, Czech Republic
VL - 7517
UR - http://dx.doi.org/10.1007/978-3-642-33140-4_29
N1 - N1 10.1007/978-3-642-33140-4_29
JO - Conference Paper
ER -
TY - Generic
T1 - Artificial intelligence methods in discrete tomography
Y1 - 2012
A1 - Mihály Gara
A1 - Péter Balázs
AB - Tomography is an imaging procedure to examine the internal structure of objects. The crosssection

images are constructed with the aid of the object’s projections. It is often necessary to

minimize the number of those projections to avoid the damage or destruction of the examined

object, since in most cases the projections are made by destructive rays.

Sometimes the number of available projections are so small that conventional methods cannot

provide satisfactory results. In these cases Discrete Tomograpy can provide acceptable solutions,

but it can only be used with the assumption the object is made of only a few materials,

thus only a small number of intensity values appear in the reconstructed cross-section image.

Although there are a lot of discrete tomographic reconstruction algorithms, only a few papers

deal with the determination of intensity values of the image, in advance. In our work we

try to fill this gap by using different learning methods. During the learning and classification

we used the projection values as input arguments.

In the second part of our talk we concentrate on Binary Tomography (a special kind of Discrete

Tomography)where it is supposed that the object is composed of onematerial. Thus, there

can be only two intensities on the cross-section image - one for the object points and one for

the background. Here, we compared our earlier presented binary tomographic evolutionary

reconstruction algorithm to two others. We present the details of the above-mentioned reconstruction

method and our experimental results. This paper is based on our previous works.

JF - Conference of PhD students in computer science. Volume of Extended Abstracts.
PB - University Szeged, Institute of Informatics
CY - Szeged
ER -
TY - Generic
T1 - Barcode Detection with Uniform Partitioning and Morphological Operations
Y1 - 2012
A1 - Péter Bodnár
A1 - László Gábor Nyúl
JF - Conference of PhD students in computer science. Volume of Extended Abstracts.
PB - University of Szeged, Institute of Informatics
CY - Szeged
ER -
TY - CHAP
T1 - Binary image reconstruction from two projections and skeletal information
T2 - Combinatorial Image Analysis
Y1 - 2012
A1 - Norbert Hantos
A1 - Péter Balázs
A1 - Kálmán Palágyi
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Jake K Aggarwal
AB - In binary tomography, the goal is to reconstruct binary images from a small set of their projections. However, especially when only two projections are used, the task can be extremely underdetermined. In this paper, we show how to reduce ambiguity by using the morphological skeleton of the image as a priori. Three different variants of our method based on Simulated Annealing are tested using artificial binary images, and compared by reconstruction time and error. © 2012 Springer-Verlag.

JF - Combinatorial Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
N1 - ScopusID: 84869986820doi: 10.1007/978-3-642-34732-0_20
JO - LNCS
ER -
TY - CHAP
T1 - A central reconstruction based strategy for selecting projection angles in binary tomography
T2 - Image Analysis and Recognition
Y1 - 2012
A1 - Péter Balázs
A1 - Joost K Batenburg
ED - Aurélio Campilho
ED - Mohamed Kamel
AB - In this paper we propose a novel strategy for selecting projection angles in binary tomography which yields significantly more accurate reconstructions than others. In contrast with previous works which are of experimental nature, the method we present is based on theoretical observations. We report on experiments for different phantom images to show the effectiveness and roboustness of our procedure. The practically important case of noisy projections is also studied. © 2012 Springer-Verlag.

JF - Image Analysis and Recognition
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
N1 - ScopusID: 84864128031doi: 10.1007/978-3-642-31295-3_45
JO - LNCS
ER -
TY - Generic
T1 - Empirical studies of reconstructing hv-convex binary matrices from horizontal and vertical projections
Y1 - 2012
A1 - Zoltán Ozsvár
A1 - Péter Balázs
JF - Conference of PhD students in computer science. Volume of Extended Abstracts.
PB - University of Szeged, Institute of Informatics
CY - Szeged
ER -
TY - CHAP
T1 - An energy minimization reconstruction algorithm for multivalued discrete tomography
T2 - Computational Modelling of Objects Represented in Images: Fundamentals, Methods and Applications III
Y1 - 2012
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
ED - Paolo Di Giamberardino
ED - Daniela Iacoviello
ED - Renato M Natal Jorge
ED - Joao Manuel R S Taveres
AB - We propose a new algorithm for multivalued discrete tomography, that reconstructs images from few projections by approximating the minimum of a suitably constructed energy function with a deterministic optimization method. We also compare the proposed algorithm to other reconstruction techniques on software phantom images, in order to prove its applicability.

JF - Computational Modelling of Objects Represented in Images: Fundamentals, Methods and Applications III
PB - CRC Press - Taylor and Frances Group
CY - London
ER -
TY - Generic
T1 - Extracting geometrical features of discrete images from their projections
Y1 - 2012
A1 - Tamás Sámuel Tasi
A1 - Péter Balázs
JF - Conference of PhD students in computer science. Volume of Extended Abstracts.
PB - University of Szeged, Institute of Informatics
CY - Szeged
ER -
TY - CHAP
T1 - Hexagonal parallel thinning algorithms based on sufficient conditions for topology preservation
T2 - Computational Modelling of Objects Represented in Images: Fundamentals, Methods and Applications III
Y1 - 2012
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Paolo Di Giamberardino
ED - Daniela Iacoviello
ED - Renato M Natal Jorge
ED - Joao Manuel R S Taveres
AB - Thinning is a well-known technique for producing skeleton-like shape features from digital

binary objects in a topology preserving way. Most of the existing thinning algorithms presuppose that the input

images are sampled on orthogonal grids.This paper presents new sufficient conditions for topology preserving

reductions working on hexagonal grids (or triangular lattices) and eight new 2D hexagonal parallel thinning

algorithms that are based on our conditions.The proposed algorithms are capable of producing both medial lines

and topological kernels as well.

JF - Computational Modelling of Objects Represented in Images: Fundamentals, Methods and Applications III
PB - CRC Press - Taylor and Frances Group
CY - London
SN - 978-0-415-62134-2
ER -
TY - CONF
T1 - Improving barcode detection with combination of simple detectors
T2 - Proceedings of the International Conference on Signal Image Technology & Internet Systems (SITIS)
Y1 - 2012
A1 - Péter Bodnár
A1 - László Gábor Nyúl
ED - Kokou Yetongnon
ED - Richard Chbeir
ED - Albert Dipanda
ED - Luigi Gallo
AB - Barcode detection is required in a wide range of real-life applications. Imaging conditions and techniques vary considerably and each application has its own requirements for detection speed and accuracy. In our earlier works we built barcode detectors using morphological operations and uniform partitioning with several approaches and showed their behaviour on a set of test images. In this work, we examine ensemble efficiency of those simple detectors using various aggregation methods. Using a combination of several simple features localization performance improves significantly.

JF - Proceedings of the International Conference on Signal Image Technology & Internet Systems (SITIS)
PB - IEEE
CY - Naples, Italy
N1 - ScopusID: 84874080233doi: 10.1109/SITIS.2012.52
ER -
TY - CONF
T1 - Isthmus-based Order-Independent Sequential Thinning
T2 - IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SSPRA)
Y1 - 2012
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - M Petrou
ED - A D Sappa
ED - A G Triantafyllidis
AB - Thinning as a layer-by-layer reduction is a frequently used technique for skeletonization. Sequential thinning algorithms usually suffer from the drawback of being order-dependent, i.e., their results depend on the visiting order of object points. Earlier order-independent sequential methods are based on the conventional thinning schemes that preserve endpoints to provide relevant geometric information of objects. These algorithms can generate centerlines in 2D and medial surfaces in 3D. This paper presents an alternative strategy for order-independent thinning which follows an approach, proposed by Bertrand and Couprie, which accumulates so-called isthmus points. The main advantage of this order-independent strategy over the earlier ones is that it makes also possible to produce centerlines of 3D objects.

JF - IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SSPRA)
PB - IASTED ACTA Press
CY - Crete, Greek
UR - http://www.actapress.com/Content_of_Proceeding.aspx?proceedingID=736
N1 - doi: 10.2316/P.2012.778-025
ER -
TY - CHAP
T1 - Machine learning as a preprocessing phase in discrete tomography
T2 - Applications of Discrete Geometry and Mathematical Morphology (WADGMM)
Y1 - 2012
A1 - Mihály Gara
A1 - Tamás Sámuel Tasi
A1 - Péter Balázs
ED - Ullrich Köthe
ED - Annick Montanvert
ED - Pierre Soille
AB - In this paper we investigate for two well-known machine learning methods, decision trees and neural networks, how they classify discrete images from their projections. As an example, we present classification results when the task is to guess the number of intensity values of the discrete image. Machine learning can be used in Discrete Tomography as a preprocessing step in order to choose the proper reconstruction algorithm or - with the aid of the knowledge acquired - to improve its accuracy. We also show how to design new evolutionary reconstruction methods that can exploit the information gained by machine learning classifiers. © 2012 Springer-Verlag.

JF - Applications of Discrete Geometry and Mathematical Morphology (WADGMM)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
N1 - ScopusID: 84865454250doi: 10.1007/978-3-642-32313-3_8
JO - LNCS
ER -
TY - BOOK
T1 - Markov random fields in image segmentation
Y1 - 2012
A1 - Zoltan Kato
A1 - Josiane Zerubia
AB - Markov Random Fields in Image Segmentation introduces the fundamentals of Markovian modeling in image segmentation as well as providing a brief overview of recent advances in the field.

PB - Now Publishers
CY - Hanover, NH
N1 - doi: 10.1561/2000000035
ER -
TY - CONF
T1 - A Multi-Layer Phase Field Model for Extracting Multiple Near-Circular Objects
T2 - International Conference on Pattern Recognition (ICPR)
Y1 - 2012
A1 - Csaba Molnar
A1 - Zoltan Kato
A1 - Ian Jermyn
ED - Jan-Olof Eklundh
ED - Yuichi Ohta
ED - Steven Tanimoto
AB - This paper proposes a functional that assigns low `energy' to sets of subsets of the image domain consisting of a number of possibly overlapping near-circular regions of approximately a given radius: a `gas of circles'. The model can be used as a prior for object extraction whenever the objects conform to the `gas of circles' geometry, e.g. cells in biological images. Configurations are represented by a multi-layer phase field. Each layer has an associated function, regions being defined by thresholding. Intra-layer interactions assign low energy to configurations consisting of non-overlapping near-circular regions, while overlapping regions are represented in separate layers. Inter-layer interactions penalize overlaps. Here we present a theoretical and experimental analysis of the model.

JF - International Conference on Pattern Recognition (ICPR)
PB - IEEE
CY - Tsukuba, Japan
SN - 978-1-4673-2216-4
ER -
TY - JOUR
T1 - Nonlinear Shape Registration without Correspondences
JF - IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE
Y1 - 2012
A1 - Csaba Domokos
A1 - Jozsef Nemeth
A1 - Zoltan Kato
AB - In this paper, we propose a novel framework to estimate the parameters of a diffeomorphism that aligns a known shape and its distorted observation. Classical registration methods first establish correspondences between the shapes and then compute the transformation parameters from these landmarks. Herein, we trace back the problem to the solution of a system of nonlinear equations which directly gives the parameters of the aligning transformation. The proposed method provides a generic framework to recover any diffeomorphic deformation without established correspondences. It is easy to implement, not sensitive to the strength of the deformation, and robust against segmentation errors. The method has been applied to several commonly used transformation models. The performance of the proposed framework has been demonstrated on large synthetic data sets as well as in the context of various applications.

PB - IEEE
VL - 34
SN - 0162-8828
UR - http://www.inf.u-szeged.hu/~kato/papers/TPAMI-2010-03-0146.R2_Kato.pdf
IS - 5
N1 - UT: 000301747400009doi: 10.1109/TPAMI.2011.200
JO - IEEE T PATTERN ANAL
ER -
TY - CONF
T1 - A novel method for accurate and efficient barcode detection with morphological operations
T2 - Proceedings of the International Conference on Signal Image Technology & Internet Systems (SITIS)
Y1 - 2012
A1 - Melinda Katona
A1 - László Gábor Nyúl
ED - Kokou Yetongnon
ED - Richard Chbeir
ED - Albert Dipanda
ED - Luigi Gallo
AB - Barcode technology is the pillar of automatic identification, that is used in a wide range of real-time applications with various types of codes. The different types of codes and applications impose special problems, so there is a continuous need for solutions with improved effectiveness. There are several methods for barcode localization, that are well characterized by accuracy and speed. Particularly, high-speed processing places need automatic barcode localization, e.g. conveyor belts, automated production, where missed detections cause loss of profit. In this paper, we mainly deal with segmentation of images with 1D barcode, but also analyze the operation of different methods for 2D barcode images as well. Our goal is to detect automatically, rapidly and accurately the barcode location by the help of extracted features. We compare some published method from the literature, which basically rely on the contrast between the background and the shape that represent the code. We also propose a novel algorithm, that outperforms the others in both accuracy and efficiency in detecting 1D codes.

JF - Proceedings of the International Conference on Signal Image Technology & Internet Systems (SITIS)
PB - IEEE
CY - Naples, Italy
SN - 978-1-4673-5152-2
N1 - ScopusID: 84874042343doi: 10.1109/SITIS.2012.53
ER -
TY - Generic
T1 - A novel optimization-based reconstruction algorithm for multivalued discrete tomography
Y1 - 2012
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
JF - Conference of PhD students in computer science. Volume of extended abstracts.
PB - University of Szeged, Institute of Informatics
CY - Szeged
ER -
TY - CONF
T1 - An optimization-based reconstruction algorithm for multivalued discrete tomography
T2 - Veszprém Optimization Conference: Advanced Algorithms (Vocal)
Y1 - 2012
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
JF - Veszprém Optimization Conference: Advanced Algorithms (Vocal)
PB - University of Pannonia
CY - Veszprém
ER -
TY - CONF
T1 - On Order–Independent Sequential Thinning
T2 - IEEE International Conference on Cognitive Infocommunications (CogInfoCom)
Y1 - 2012
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - IEEE
AB - The visual world composed by the human and computational cognitive systems strongly relies on shapes of objects. Skeleton is a widely applied shape feature that plays an important role in many fields of image processing, pattern recognition, and computer vision. Thinning is a frequently used, iterative object reduction strategy for skeletonization. Sequential thinning algorithms, which are based on contour tracking, delete just one border point at a time. Most of them have the disadvantage of order-dependence, i.e., for dissimilar visiting orders of object points, they may generate different skeletons. In this work, we give a survey of our results on order-independent thinning: we introduce some sequential algorithms that produce identical skeletons for any visiting orders, and we also present some sufficient conditions for the order-independence of templatebased sequential algorithms.

JF - IEEE International Conference on Cognitive Infocommunications (CogInfoCom)
PB - IEEE
CY - Kosice, Slovakia
SN - 978-1-4673-5187-4
UR - http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=6413305
ER -
TY - CHAP
T1 - Parametric Stochastic Modeling for Color Image Segmentation and Texture Characterization
T2 - Advanced color image processing and analysis
Y1 - 2012
A1 - Imtnan-Ul-Haque Qazi
A1 - Oliver Alata
A1 - Zoltan Kato
ED - Christine Fernandez-Maloigne
AB - *Black should be made a color of light* Clemence Boulouque

Parametric stochastic models offer the definition of color and/or texture features based on model parameters, which is of interest for color texture classification, segmentation and synthesis.

In this chapter, distribution of colors in the images through various parametric approximations including multivariate Gaussian distribution, multivariate Gaussian mixture models (MGMM) and Wishart distribution, is discussed. In the context of Bayesian color image segmentation, various aspects of sampling from the posterior distributions to estimate the color distribution from MGMM and the label field, using different move types are also discussed. These include reversible jump mechanism from MCMC methodology. Experimental results on color images are presented and discussed.

Then, we give some materials for the description of color spatial structure using Markov Random Fields (MRF), and more particularly multichannel GMRF, and multichannel linear prediction models. In this last approach, two dimensional complex multichannel versions of both causal and non-causal models are discussed to perform the simultaneous parametric power spectrum estimation of the luminance and the chrominance channels of the color image. Application of these models to the classification and segmentation of color texture images is also illustrated.

JF - Advanced color image processing and analysis
PB - Springer
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
SN - 978-1-4419-6189-1
ER -
TY - CONF
T1 - Perimeter estimation of some discrete sets from horizontal and vertical projections
T2 - IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA)
Y1 - 2012
A1 - Tamás Sámuel Tasi
A1 - M Hegedűs
A1 - Péter Balázs
ED - M Petrou
ED - A D Sappa
ED - A G Triantafyllidis
AB - In this paper, we design neural networks to estimate the perimeter of simple and more complex discrete sets from their horizontal and vertical projections. The information extracted this way can be useful to simplify the problem of reconstructing the discrete set from its projections, which task is in focus of discrete tomography. Beside presenting experimental results with neural networks, we also reveal some statistical properties of the perimeter of the studied discrete sets.

JF - IASTED International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA)
PB - IASTED ACTA Press
CY - Crete, Greek
N1 - ScopusID: 84864772360doi: 10.2316/P.2012.778-017
ER -
TY - CONF
T1 - Simultaneous Affine Registration of Multiple Shapes
T2 - International Conference on Pattern Recognition (ICPR)
Y1 - 2012
A1 - Csaba Domokos
A1 - Zoltan Kato
ED - Jan-Olof Eklundh
ED - Yuichi Ohta
ED - Steven Tanimoto
AB - The problem of simultaneously estimating affine deformations between multiple objects occur in many applications. Herein, a direct method is proposed which provides the result as a solution of a linear system of equations without establishing correspondences between the objects. The key idea is to construct enough linearly independent equations using covariant functions, and then finding the solution simultaneously for all affine transformations. Quantitative evaluation confirms the performance of the method.

JF - International Conference on Pattern Recognition (ICPR)
PB - IEEE
CY - Tsukuba, Japan
SN - 978-1-4673-2216-4
ER -
TY - CONF
T1 - Solving binary tomography from morphological skeleton via optimization
T2 - Veszprém Optimization Conference: Advanced Algorithms (VOCAL)
Y1 - 2012
A1 - Norbert Hantos
A1 - Péter Balázs
A1 - Kálmán Palágyi
JF - Veszprém Optimization Conference: Advanced Algorithms (VOCAL)
PB - University of Pannonia
CY - Veszprém
ER -
TY - CONF
T1 - Spectral clustering to model deformations for fast multimodal prostate registration
T2 - International Conference on Pattern Recognition (ICPR)
Y1 - 2012
A1 - Jhimli Mitra
A1 - Zoltan Kato
A1 - Soumya Ghose
A1 - Desire Sidibe
A1 - Robert Martí
A1 - Xavier Lladó
A1 - Oliver Arnau
A1 - Joan C Vilanova
A1 - Fabrice Meriaudeau
ED - Jan-Olof Eklundh
ED - Yuichi Ohta
ED - Steven Tanimoto
AB - This paper proposes a method to learn deformation parameters off-line for fast multimodal registration of ultrasound and magnetic resonance prostate images during ultrasound guided needle biopsy. The registration method involves spectral clustering of the deformation parameters obtained from a spline-based nonlinear diffeomorphism between training magnetic resonance and ultrasound prostate images. The deformation models built from the principal eigen-modes of the clusters are then applied on a test magnetic resonance image to register with the test ultrasound prostate image. The deformation model with the least registration error is finally chosen as the optimal model for deformable registration. The rationale behind modeling deformations is to achieve fast multimodal registration of prostate images while maintaining registration accuracies which is otherwise computationally expensive. The method is validated for 25 patients each with a pair of corresponding magnetic resonance and ultrasound images in a leave-one-out validation framework. The average registration accuracies i.e. Dice similarity coefficient of 0.927 ± 0.025, 95% Hausdorff distance of 5.14 ± 3.67 mm and target registration error of 2.44 ± 1.17 mm are obtained by our method with a speed-up in computation time by 98% when compared to Mitra et al. [7].

JF - International Conference on Pattern Recognition (ICPR)
PB - IEEE
CY - Tsukuba, Japan
SN - 978-1-4673-2216-4
UR - http://hal.archives-ouvertes.fr/docs/00/71/09/43/PDF/ICPR_Jhimli.pdf
ER -
TY - JOUR
T1 - A spline-based non-linear diffeomorphism for multimodal prostate registration.
JF - MEDICAL IMAGE ANALYSIS
Y1 - 2012
A1 - Jhimli Mitra
A1 - Zoltan Kato
A1 - Robert Martí
A1 - Oliver Arnau
A1 - Xavier Lladó
A1 - Desire Sidibe
A1 - Soumya Ghose
A1 - Joan C Vilanova
A1 - Josep Comet
A1 - Fabrice Meriaudeau
AB - This paper presents a novel method for non-rigid registration of transrectal ultrasound and magnetic resonance prostate images based on a non-linear regularized framework of point correspondences obtained from a statistical measure of shape-contexts. The segmented prostate shapes are represented by shape-contexts and the Bhattacharyya distance between the shape representations is used to find the point correspondences between the 2D fixed and moving images. The registration method involves parametric estimation of the non-linear diffeomorphism between the multimodal images and has its basis in solving a set of non-linear equations of thin-plate splines. The solution is obtained as the least-squares solution of an over-determined system of non-linear equations constructed by integrating a set of non-linear functions over the fixed and moving images. However, this may not result in clinically acceptable transformations of the anatomical targets. Therefore, the regularized bending energy of the thin-plate splines along with the localization error of established correspondences should be included in the system of equations. The registration accuracies of the proposed method are evaluated in 20 pairs of prostate mid-gland ultrasound and magnetic resonance images. The results obtained in terms of Dice similarity coefficient show an average of 0.980+/-0.004, average 95% Hausdorff distance of 1.63+/-0.48mm and mean target registration and target localization errors of 1.60+/-1.17mm and 0.15+/-0.12mm respectively.

VL - 16
SN - 1361-8415
IS - 6
N1 - UT: 000309694100015ScopusID: 84866118888doi: 10.1016/j.media.2012.04.006
JO - MED IMAGE ANAL
ER -
TY - CHAP
T1 - On topology preservation for triangular thinning algorithms
T2 - Combinatorial Image Analysis (IWCIA)
Y1 - 2012
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Jake K Aggarwal
AB - Thinning is a frequently used strategy to produce skeleton-like shape features of binary objects. One of the main problems of parallel thinning is to ensure topology preservation. Solutions to this problem have been already given for the case of orthogonal and hexagonal grids. This work introduces some characterizations of simple pixels and some sufficient conditions for parallel thinning algorithms working on triangular grids (or hexagonal lattices) to preserve topology.

JF - Combinatorial Image Analysis (IWCIA)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Austin, TX, USA
SN - 978-3-642-34731-3
N1 - doi: 10.1007/978-3-642-34732-0_10Lecture Notes in Computer Science, Volume 7655
JO - LNCS
ER -
TY - CHAP
T1 - Topology Preserving Parallel 3D Thinning Algorithms
T2 - Digital Geometry Algorithms
Y1 - 2012
A1 - Kálmán Palágyi
A1 - Gábor Németh
A1 - Péter Kardos
ED - Valentin E Brimkov
ED - Reneta P Barneva
AB - A widely used technique to obtain skeletons of binary objects is thinning, which is an iterative layer-by-layer erosion in a topology preserving way. Thinning in 3D is capable of extracting various skeleton-like shape descriptors (i.e., centerlines, medial surfaces, and topological kernels). This chapter describes a family of new parallel 3D thinning algorithms for (26, 6) binary pictures. The reported algorithms are derived from some sufficient conditions for topology preserving parallel reduction operations, hence their topological correctness is guaranteed. ` `

JF - Digital Geometry Algorithms
T3 - Lecture Notes in Computational Vision and Biomechanics
PB - Springer-Verlag
SN - 978-94-007-4173-7
N1 - doi: 10.1007/978-94-007-4174-4_6
ER -
TY - CHAP
T1 - A Unifying Framework for Correspondence-less Linear Shape Alignment
T2 - International Conference on Image Analysis and Recognition (ICIAR)
Y1 - 2012
A1 - Zoltan Kato
ED - Aurélio Campilho
AB - We consider the estimation of linear transformations aligning a known binary shape and its distorted observation. The classical way to solve this registration problem is to find correspondences between the two images and then compute the transformation parameters from these landmarks. Here we propose a unified framework where the exact transformation is obtained as the solution of either a polynomial or a linear system of equations without establishing correspondences. The advantages of the proposed solutions are that they are fast, easy to implement, have linear time complexity, work without landmark correspondences and are independent of the magnitude of transformation.

JF - International Conference on Image Analysis and Recognition (ICIAR)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Aveiro, Portugal
SN - 978-3-642-31294-6
N1 - UT: 000323558000033
JO - LNCS
ER -
TY - CONF
T1 - A Unifying Framework for Non-linear Registration of 3D Objects
T2 - IEEE International Conference on Cognitive Infocommunications (CogInfoCom)
Y1 - 2012
A1 - Zsolt Santa
A1 - Zoltan Kato
AB - An extension of our earlier work is proposed to find a non-linear aligning transformation between a pair of deformable 3D objects. The basic idea is to set up a system of nonlinear equations whose solution directly provides the parameters of the aligning transformation. Each equation is generated by integrating a nonlinear function over the object's domains. Thus the number of equations is determined by the number of adopted nonlinear functions yielding a flexible mechanism to generate sufficiently many equations. While classical approaches would establish correspondences between the shapes, our method works without landmarks. Experiments with 3D polynomial and thin plate spline deformations confirm the performance of the framework.

JF - IEEE International Conference on Cognitive Infocommunications (CogInfoCom)
PB - IEEE
CY - Kosice, Slovakia
SN - 978-1-4673-5187-4
UR - http://www.inf.u-szeged.hu/~kato/papers/coginfocomm2012.pdf
N1 - UT: 000320454200086
ER -
TY - CONF
T1 - 2D Parallel Thinning Algorithms Based on Isthmus-Preservation
T2 - Proceedings of the International Symposium on Image and Signal Processing and Analysis (ISPA)
Y1 - 2011
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - Sven Lončarić
ED - Giovanni Ramponi
ED - D. Sersic
AB - Skeletons are widely used shape descriptors which summarize the general form of binary objects. A technique to obtain skeletons is the thinning, that is an iterative layer-by-layer erosion in a topology-preserving way. Conventional thinning algorithms preserve line endpoints to provide important geometric information relative to the object to be represented. Bertrand and Couprie proposed an alternative strategy by accumulating isthmus points that are line interior points. In this paper we present six new 2D parallel thinning algorithms that are derived from some sufficient conditions for topology preserving reductions and based on isthmus-preservation.

JF - Proceedings of the International Symposium on Image and Signal Processing and Analysis (ISPA)
PB - IEEE
CY - Dubrovnik, Croatia
SN - 978-1-4577-0841-1
N1 - ScopusID: 83455172782
ER -
TY - JOUR
T1 - 2D parallel thinning and shrinking based on sufficient conditions for topology preservation
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2011
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
AB - Thinning and shrinking algorithms, respectively, are capable of extracting medial lines and topological kernels from digital binary objects in a topology preserving way. These topological algorithms are composed of reduction operations: object points that satisfy some topological and geometrical constraints are removed until stability is reached. In this work we present some new sufficient conditions for topology preserving parallel reductions and fiftyfour new 2D parallel thinning and shrinking algorithms that are based on our conditions. The proposed thinning algorithms use five characterizations of endpoints.

PB - University of Szeged, Institute of Informatics
CY - Szeged
VL - 20
SN - 0324-721X
IS - 1
N1 - ScopusID: 79960666919
JO - ACTA CYBERN-SZEGED
ER -
TY - CONF
T1 - 3D objektumok lineáris deformációinak becslése
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Attila Tanacs
A1 - Joakim Lindblad
A1 - Nataša Sladoje
A1 - Zoltan Kato
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
ER -
TY - CONF
T1 - Affin Puzzle: Deformált objektumdarabok helyreállítása megfeleltetések nélkül
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Csaba Domokos
A1 - Zoltan Kato
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
UR - http://www.inf.u-szeged.hu/kepaf2011/pdfs/S05_03.pdf
N1 - Kuba Attila Díjas cikk.
ER -
TY - JOUR
T1 - Conference of PhD Students in Computer Science
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2011
A1 - Kálmán Palágyi
VL - 20
SN - 0324-721X
IS - 1
N1 - ScopusID: 79960683318
JO - ACTA CYBERN-SZEGED
ER -
TY - JOUR
T1 - Direction-dependency of binary tomographic reconstruction algorithms
JF - GRAPHICAL MODELS
Y1 - 2011
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
AB - In this work we study the relation between the quality of a binary tomographic reconstruction and the choice of angles of the projections. We conduct experiments on a set of software phantoms by reconstructing them from different projection sets using three different discrete tomography reconstruction algorithms, and compare the accuracy of the corresponding reconstructions with suitable approaches. To validate our results for possible real-world applications, we conduct the experiments by adding random noise of different characteristics to the simulated projection data, and by applying small topological changes on the phantom images as well. In addition, we also discuss some consequences of the angle-selection dependency and possible practical applications arising from the field of non-destructive testing, too.

VL - 73
SN - 1524-0703
IS - 6
N1 - UT: 000296999100028ScopusID: 80054709026doi: 10.1016/j.gmod.2011.06.006
JO - GRAPH MODELS
ER -
TY - CONF
T1 - Élősejt szegmentálása gráfvágás segítségével fluoreszcenciás mikroszkóp képeken
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Milan Lesko
A1 - Zoltan Kato
A1 - Antal Nagy
A1 - Imre Gombos
A1 - Zsolt Török
A1 - László Vígh
A1 - László Vígh
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
UR - http://www.inf.u-szeged.hu/kepaf2011/pdfs/S08_02.pdf
ER -
TY - CHAP
T1 - A family of topology-preserving 3d parallel 6-subiteration thinning algorithms
T2 - Combinatorial Image Analysis (IWCIA)
Y1 - 2011
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Jake K Aggarwal
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Kostadin N Koroutchev
ED - Elka R Korutcheva
AB - Thinning is an iterative layer-by-layer erosion until only the skeleton-like shape features of the objects are left. This paper presents a family of new 3D parallel thinning algorithms that are based on our new sufficient conditions for 3D parallel reduction operators to preserve topology. The strategy which is used is called subiteration-based: each iteration step is composed of six parallel reduction operators according to the six main directions in 3D. The major contributions of this paper are: 1) Some new sufficient conditions for topology preserving parallel reductions are introduced. 2) A new 6-subiteration thinning scheme is proposed. Its topological correctness is guaranteed, since its deletion rules are derived from our sufficient conditions for topology preservation. 3) The proposed thinning scheme with different characterizations of endpoints yields various new algorithms for extracting centerlines and medial surfaces from 3D binary pictures. © 2011 Springer-Verlag Berlin Heidelberg.

JF - Combinatorial Image Analysis (IWCIA)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Madrid, Spain
SN - 978-3-642-21072-3
N1 - ScopusID: 79957651399doi: 10.1007/978-3-642-21073-0_5
JO - LNCS
ER -
TY - CONF
T1 - Fast linear registration of 3D objects segmented from medical images
T2 - Biomedical Engineering and Informatics (BMEI)
Y1 - 2011
A1 - Attila Tanacs
A1 - Zoltan Kato
ED - Yongsheng Ding
ED - Yonghong Peng
ED - Riyi Shi
ED - Kuangrong Hao
ED - Lipo Wang
AB - In this paper a linear registration framework is used for medical image registration using segmented binary objects. The method is best suited for problems where the segmentation is available, but we also propose a general bone segmentation approach for CT images. We focus on the case when the objects to be registered differ considerably because of segmentation errors. We check the applicability of the method to bone segmentation of pelvic and thoracic CT images. Comparison is also made against a classical mutual information-based registration method. © 2011 IEEE.

JF - Biomedical Engineering and Informatics (BMEI)
PB - IEEE
CY - Shanghai
SN - 978-1-4244-9351-7
N1 - ScopusID: 84855764850doi: 10.1109/BMEI.2011.6098290
ER -
TY - BOOK
T1 - Fejlett Grafikai Algoritmusok
Y1 - 2011
A1 - Antal Nagy
PB - Typotex Kiadó
CY - Budapest
ER -
TY - CONF
T1 - Iterációnkénti simítással kombinált vékonyítás
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Péter Kardos
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
UR - http://www.inf.u-szeged.hu/kepaf2011/pdfs/S05_01.pdf
ER -
TY - BOOK
T1 - Képfeldolgozás haladóknak
Y1 - 2011
A1 - Kálmán Palágyi
PB - Typotex
CY - Budapest
ER -
TY - CONF
T1 - Mediánszűrés alkalmazása algebrai rekonstrukciós módszerekben
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Norbert Hantos
A1 - Péter Balázs
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
ER -
TY - Generic
T1 - MIPPR 2011: Multispectral Image Acquisition, Processing, and Analysis
T2 - Multispectral Image Acquisition, Processing, and Analysis (MIPPR)
Y1 - 2011
ED - Zhigou Cao
ED - Aaron Fenster
ED - László Gábor Nyúl
ED - Chao Cai
JF - Multispectral Image Acquisition, Processing, and Analysis (MIPPR)
PB - SPIE
CY - Guilin, China
VL - 8002
N1 - doi: 10.1117/12.910237
ER -
TY - CONF
T1 - A non-linear diffeomorphic framework for prostate multimodal registration
T2 - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
Y1 - 2011
A1 - Jhimli Mitra
A1 - Zoltan Kato
A1 - Robert Martí
A1 - Oliver Arnau
A1 - Xavier Lladó
A1 - Soumya Ghose
A1 - Joan C Vilanova
A1 - Fabrice Meriaudeau
AB - This paper presents a novel method for non-rigid registration of prostate multimodal images based on a nonlinear framework. The parametric estimation of the non-linear diffeomorphism between the 2D fixed and moving images has its basis in solving a set of non-linear equations of thin-plate splines. The regularized bending energy of the thin-plate splines along with the localization error of established correspondences is jointly minimized with the fixed and transformed image difference, where, the transformed image is represented by the set of non-linear equations defined over the moving image. The traditional thin-plate splines with established correspondences may provide good registration of the anatomical targets inside the prostate but may fail to provide improved contour registration. On the contrary, the proposed framework maintains the accuracy of registration in terms of overlap due to the non-linear thinplate spline functions while also producing smooth deformations of the anatomical structures inside the prostate as a result of established corrspondences. The registration accuracies of the proposed method are evaluated in 20 pairs of prostate midgland ultrasound and magnetic resonance images in terms of Dice similarity coefficient with an average of 0.982 ± 0.004, average 95% Hausdorff distance of 1.54 ± 0.46 mm and mean target registration and target localization errors of 1.90±1.27 mm and 0.15 ± 0.12 mm respectively. © 2011 IEEE.

JF - International Conference on Digital Image Computing: Techniques and Applications (DICTA)
PB - IEEE
CY - Noosa, QLD
SN - 978-1-4577-2006-2
N1 - ScopusID: 84856980939doi: 10.1109/DICTA.2011.14
ER -
TY - COMP
T1 - Nonlinear Shape Registration without Correspondences
Y1 - 2011
A1 - Zoltán Kornél Török
A1 - Csaba Domokos
A1 - Jozsef Nemeth
A1 - Zoltan Kato
AB - This is the sample implementation and benchmark dataset of the nonlinear registration of 2D shapes described in the following papers: Csaba Domokos, Jozsef Nemeth, and Zoltan Kato. Nonlinear Shape Registration without Correspondences. IEEE Transactions on Pattern Analysis and Machine Intelligence, 34(5):943--958, May 2012. Note that the current demo program implements only planar homography deformations. Other deformations can be easily implemented based on the demo code.

UR - http://www.inf.u-szeged.hu/~kato/software/planarhombinregdemo.html
ER -
TY - CONF
T1 - Order-independent sequential thinning in arbitrary dimensions
T2 - Signal and Image Processing and Applications (SIPA)
Y1 - 2011
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Ioannis Andreadis
ED - M Zervakis
AB - Skeletons are region based shape descriptors that play important role in shape representation. This paper introduces a novel sequential thinning approach for n-dimensional binary objects (*n* =1,2,3, ...). Its main strength lies in its order--independency, i.e., it can produce the same skeletons for any visiting orders of border points. Furthermore, this is the first scheme in this field that is also applicable for higher dimensions.

JF - Signal and Image Processing and Applications (SIPA)
PB - IASTED - Acta Press
CY - Crete, Greek
N1 - doi: 10.2316/P.2011.738-021
ER -
TY - CHAP
T1 - Orvosi képfeldolgozás, Orvosi algoritmusok, Távérzékelés, mikroszkópia
T2 - Képi információ mérése
Y1 - 2011
A1 - Attila Tanacs
A1 - László Czúni
A1 - Attila Tanacs
JF - Képi információ mérése
PB - Typotex Kiadó
CY - Budapest
ER -
TY - THES
T1 - Parametric Estimation of Affine Deformations without Correspondences
Y1 - 2011
A1 - Csaba Domokos
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - JOUR
T1 - Projection selection dependency in binary tomography
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2011
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
AB - It has already been shown that the choice of projection angles can significantly influence the quality of reconstructions in discrete tomography. In this contribution we summarize and extend the previous results by explaining and demonstrating tile effects of projection selection dependency, in a set of experimental software tests. We perform reconstructions of software phantoms, by using different binary tomography reconstruction algorithms, from different equiangular and non-equiangular projections sets, under various conditions (i.e., when the objects to be reconstructed undergo slight topological changes, or the projection data is affected by noise) and compare the results with suitable approaches. Based on our observations, we reveal regularities in the resulting data and discuss possible consequences of such projection selection dependency in binary tomography.

PB - University of Szeged, Institute of Informatics
CY - Szeged
VL - 20
SN - 0324-721X
IS - 1
N1 - ScopusID: 79960679541
JO - ACTA CYBERN-SZEGED
ER -
TY - JOUR
T1 - Sufficient conditions for order-independency in sequential thinning
JF - Acta Cybernetica
Y1 - 2011
A1 - Péter Kardos
AB - The main issue of this paper is to introduce some conditions for template-based sequential thinning that are capable of producing the same skeleton for a given binary image, independent of the visiting order of object points. As an example, we introduce two order-independent thinning algorithms for 2D binary images that satisfy these conditions. ` `

PB - University of Szeged
VL - 20
ER -
TY - BOOK
T1 - Számítógépes látás
Y1 - 2011
A1 - Zoltan Kato
A1 - László Czúni
PB - Typotex Kiadó
CY - Budapest
ER -
TY - CONF
T1 - Tehetséggondozó program a Szegedi Tudományegyetem Informatikai Tanszékcsoport BSc szakjain
T2 - Informatika a felsőoktatásban 2011 konferencia
Y1 - 2011
A1 - Péter Balázs
A1 - Zoltán L Németh
ED - László Cser
ED - Miklós Herdon
JF - Informatika a felsőoktatásban 2011 konferencia
PB - Debreceni Egyetem Informatikai Kar
CY - Debrecen
ER -
TY - JOUR
T1 - Thinning combined with iteration-by-iteration smoothing for 3D binary images
JF - GRAPHICAL MODELS
Y1 - 2011
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
AB - In this work we present a new thinning scheme for reducing the noise sensitivity of 3D thinning algorithms. It uses iteration-by-iteration smoothing that removes some border points that are considered as extremities. The proposed smoothing algorithm is composed of two parallel topology preserving reduction operators. An efficient implementation of our algorithm is sketched and its topological correctness for (26, 6) pictures is proved. © 2011 Elsevier Inc. All rights reserved.

VL - 73
SN - 1524-0703
IS - 6
N1 - ScopusID: 79952613010doi: 10.1016/j.gmod.2011.02.001
JO - GRAPH MODELS
ER -
TY - CONF
T1 - A topológia-megőrzés elegendő feltételein alapuló 3D párhuzamos vékonyító algoritmusok
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
UR - http://www.inf.u-szeged.hu/kepaf2011/pdfs/S05_02.pdf
ER -
TY - CHAP
T1 - On topology preservation for hexagonal parallel thinning algorithms
T2 - Combinatorial Image Analysis (IWCIA)
Y1 - 2011
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Jake K Aggarwal
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Kostadin N Koroutchev
ED - Elka R Korutcheva
AB - Topology preservation is the key concept in parallel thinning algorithms on any sampling schemes. This paper establishes some sufficient conditions for parallel thinning algorithms working on hexagonal grids (or triangular lattices) to preserve topology. By these results, various thinning (and shrinking to a residue) algorithms can be verified. To illustrate the usefulness of our sufficient conditions, we propose a new parallel thinning algorithm and prove its topological correctness. © 2011 Springer-Verlag Berlin Heidelberg.

JF - Combinatorial Image Analysis (IWCIA)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Madrid, Spain
SN - 978-3-642-21072-3
N1 - ScopusID: 79957628214doi: 10.1007/978-3-642-21073-0_6
JO - LNCS
ER -
TY - JOUR
T1 - Topology Preserving Parallel Thinning Algorithms
JF - INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY
Y1 - 2011
A1 - Gábor Németh
A1 - Kálmán Palágyi
AB - Thinning is an iterative object reduction technique for extracting medial curves from binary objects. During a thinning process, some border points that satisfy certain topological and geometric constraints are deleted in iteration steps. Parallel thinning algorithms are composed of parallel reduction operators that delete a set of object points simultaneously. This article presents 21 parallel thinning algorithms for (8,4) binary pictures that are derived from the sufficient conditions for topology preservation accommodated to the three parallel thinning approaches. © 2011 Wiley Periodicals, Inc.

PB - Wiley Periodicals, Inc.
VL - 21
SN - 0899-9457
IS - 1
N1 - UT: 000287789100005ScopusID: 79951782238doi: 10.1002/ima.20272
JO - INT J IMAG SYST TECH
ER -
TY - CONF
T1 - Vetületi irányfüggőség a bináris tomográfiában
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
Y1 - 2011
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
ED - Zoltan Kato
ED - Kálmán Palágyi
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2011
PB - NJSZT
CY - Szeged
ER -
TY - Generic
T1 - VIII. Magyar Számítógépes Nyelvészeti Konferencia
T2 - Magyar Számítógépes Nyelvészeti Konferencia
Y1 - 2011
ED - Attila Tanacs
ED - Veronika Vincze
JF - Magyar Számítógépes Nyelvészeti Konferencia
PB - Szegedi Tudományegyetem
CY - Szeged
SN - 978-963-306-121-3
UR - http://www.inf.u-szeged.hu/mszny2011/
ER -
TY - CHAP
T1 - Affine puzzle: Realigning deformed object fragments without correspondences
T2 - European Conference on Computer Vision (ECCV)
Y1 - 2010
A1 - Csaba Domokos
A1 - Zoltan Kato
ED - Kostas Daniilidis
ED - Petros Maragos
ED - Nikos Paragios
AB - This paper is addressing the problem of realigning broken objects without correspondences. We consider linear transformations between the object fragments and present the method through 2D and 3D affine transformations. The basic idea is to construct and solve a polynomial system of equations which provides the unknown parameters of the alignment. We have quantitatively evaluated the proposed algorithm on a large synthetic dataset containing 2D and 3D images. The results show that the method performs well and robust against segmentation errors. We also present experiments on 2D real images as well as on volumetric medical images applied to surgical planning. © 2010 Springer-Verlag.

JF - European Conference on Computer Vision (ECCV)
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Crete, Greece
SN - 978-3-642-15551-2
N1 - UT: 000286164000056ScopusID: 78149337447doi: 10.1007/978-3-642-15552-9_56
JO - LNCS
ER -
TY - ABST
T1 - Angular Stable Locking System. Milestone in IM nailing? ASLS
Y1 - 2010
A1 - Endre Varga
A1 - Balázs Erdőhelyi
N1 - [Előadás]
[Előadás]
ER -
TY - JOUR
T1 - Bejárásfüggetlen szekvenciális vékonyítás
JF - ALKALMAZOTT MATEMATIKAI LAPOK
Y1 - 2010
A1 - Péter Kardos
A1 - Gábor Németh
A1 - Kálmán Palágyi
VL - 27
SN - 0133-3399
IS - 1
JO - ALKALMAZOTT MATEMATIKAI LAPOK
ER -
TY - CONF
T1 - Binary tomographic reconstruction with an object-based evolutionary algorithm
T2 - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
Y1 - 2010
A1 - Mihály Gara
A1 - Péter Balázs
JF - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
PB - University of Szeged
CY - Szeged
ER -
TY - CHAP
T1 - Direction-dependency of a binary tomographic reconstruction algorithm
T2 - Computational Modeling of Objects Represented in Images
Y1 - 2010
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Herbert A Hauptman
ED - Renato M Natal Jorge
ED - João Manuel R S Tavares
AB - We study how the quality of an image reconstructed by a binary tomographic algorithm depends on the direction of the observed object in the scanner, if only a few projections are available. To do so we conduct experiments on a set of software phantoms by reconstructing them form different projection sets using an algorithm based on D.C. programming (a method for minimizing the difference of convex functions), and compare the accuracy of the corresponding reconstructions by two suitable approaches. Based on the experiments, we discuss consequences on applications arising from the field of non-destructive testing, as well.

JF - Computational Modeling of Objects Represented in Images
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Buffalo, NY, USA
SN - 978-3-642-12711-3
N1 - UT: 000279020400022ScopusID: 77952365308doi: 10.1007/978-3-642-12712-0_22
JO - LNCS
ER -
TY - CHAP
T1 - Estimation of linear deformations of 3D objects
T2 - IEEE International Conference on Image Processing (ICIP)
Y1 - 2010
A1 - Attila Tanacs
A1 - Joakim Lindblad
A1 - Nataša Sladoje
A1 - Zoltan Kato
AB - We propose a registration method to find affine transformations between 3D objects by constructing and solving an overdetermined system of polynomial equations. We utilize voxel coverage information for more precise object boundary description. An iterative solution enables us to easily adjust the method to recover e.g. rigid-body and similarity transformations. Synthetic tests show the advantage of the voxel coverage representation, and reveal the robustness properties of our method against different types of segmentation errors. The method is tested on a real medical CT volume. © 2010 IEEE.

JF - IEEE International Conference on Image Processing (ICIP)
PB - IEEE
CY - Hong Kong, Hong Kong
N1 - UT: 000287728000038ScopusID: 78651064516doi: 10.1109/ICIP.2010.5650932
ER -
TY - JOUR
T1 - Glaucoma Risk Index: Automated glaucoma detection from color fundus images
JF - MEDICAL IMAGE ANALYSIS
Y1 - 2010
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
A1 - Georg Michelson
AB - Glaucoma as a neurodegeneration of the optic nerve is one of themost common causes of blindness. Because revitalization of the degenerated nerve fibers of the optic nerve is impossible early detection of the disease is essential. This can be supported by a robust and automated mass-screening. We propose a novel automated glaucoma detection system that operates on inexpensive to acquire and widely used digital color fundus images. After a glaucoma specific preprocessing, different generic feature types are compressed by an appearance-based dimension reduction technique. Subsequently, a probabilistic two-stage classification scheme combines these features types to extract the novel Glaucoma Risk Index (GRI) that shows a reasonable glaucoma detection performance. On a sample set of 575 fundus images a classification accuracy of 80% has been achieved in a 5-fold cross-validation setup. The GRI gains a competitive area under ROC (AUC) of 88% compared to the established topography- based glaucoma probability score of scanning laser tomography with AUC of 87%. The proposed color fundus image-based GRI achieves a competitive and reliable detection performance on a low-priced modality by the statistical analysis of entire images of the optic nerve head.

VL - 14
SN - 1361-8415
IS - 3
N1 - UT: 000278255900016ScopusID: 77951645182doi: 10.1016/j.media.2009.12.006
JO - MED IMAGE ANAL
ER -
TY - THES
T1 - Image analysis methods for medical research, diagnostic and therapeutic applications
Y1 - 2010
A1 - László Gábor Nyúl
ER -
TY - CHAP
T1 - Image enhancement by median filters in algebraic reconstruction methods: an experimental study
T2 - Advances in Visual Computing
Y1 - 2010
A1 - Norbert Hantos
A1 - Péter Balázs
ED - George Bebis
ED - Richard Boyle
ED - Bahram Parvin
ED - Darko Koracin
ED - Ronald Chung
ED - Riad Hammound
ED - Muhammad Hussain
ED - Tan Kar-Han
ED - Roger Crawfis
ED - Daniel Thalmann
ED - David Kao
ED - Lisa Avila
AB - Algebraic methods for image reconstruction provide good solutions even if only few projections are available. However, they can create noisy images if the number of iterations or the computational time is limited. In this paper, we show how to decrease the effect of noise by using median filters during the iterations. We present an extensive study by applying filters of different sizes and in various times of the reconstruction process. Also, our test images are of different structural complexity. Our study concentrates on the ART and its discrete variant DART reconstruction methods.

JF - Advances in Visual Computing
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Las Vegas, NV, USA
SN - 978-3-642-17276-2
N1 - UT: 000290358400035ScopusID: 78650793785doi: 10.1007/978-3-642-17277-9_35
JO - LNCS
ER -
TY - CHAP
T1 - Live cell segmentation in fluorescence microscopy via graph cut
T2 - 20th international conference on pattern recognition (ICPR 2010)
Y1 - 2010
A1 - Milan Lesko
A1 - Zoltan Kato
A1 - Antal Nagy
A1 - Imre Gombos
A1 - Zsolt Török
A1 - László Vígh
A1 - László Vígh
ED - Aytul Ercil
AB - We propose a novel Markovian segmentation model which takes into account edge information. By construction, the model uses only pairwise interactions and its energy is submodular. Thus the exact energy minima is obtained via a max-flow/min-cut algorithm. The method has been quantitatively evaluated on synthetic images as well as on fluorescence microscopic images of live cells. © 2010 IEEE.

JF - 20th international conference on pattern recognition (ICPR 2010)
PB - IEEE
CY - Istanbul, Turkey
SN - 978-1-4244-7542-1
N1 - ScopusID: 78149486419doi: 10.1109/ICPR.2010.367Besorolás: Konferenciaközlemény
ER -
TY - CHAP
T1 - Machine learning for supporting binary tomographic reconstruction
T2 - Workshop on Applications of Discrete Geometry in Mathematical Morphology
Y1 - 2010
A1 - Péter Balázs
A1 - Mihály Gara
A1 - Tamás Sámuel Tasi
ED - Ullrich Köthe
ED - Annick Montanvert
ED - Pierre Soille
JF - Workshop on Applications of Discrete Geometry in Mathematical Morphology
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Istambul, Turkey
JO - LNCS
ER -
TY - CONF
T1 - Object rotation effects on binary tomographic reconstruction
T2 - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
Y1 - 2010
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
JF - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CONF
T1 - Obtaining geometrical properties of binary images from two projections using neural networks
T2 - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
Y1 - 2010
A1 - Tamás Sámuel Tasi
A1 - Péter Balázs
JF - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CHAP
T1 - Parallel Thinning Algorithms Based on Ronse's Sufficient Conditions for Topology Preservation
T2 - Progress in Combinatorial Image Analysis
Y1 - 2010
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - Petra Wiederhold
ED - Reneta P Barneva
JF - Progress in Combinatorial Image Analysis
PB - Scientific Research Publishing Inc.
CY - Singapore
UR - http://rpsonline.com.sg/rpsweb/iwcia09.html
ER -
TY - JOUR
T1 - Parametric estimation of affine deformations of planar shapes
JF - PATTERN RECOGNITION
Y1 - 2010
A1 - Csaba Domokos
A1 - Zoltan Kato
VL - 43
SN - 0031-3203
IS - 3
N1 - UT: 000273094100003doi: 10.1016/j.patcog.2009.08.013
JO - PATTERN RECOGN
ER -
TY - CHAP
T1 - Projection selection algorithms for discrete tomography
T2 - Advanced Concepts for Intelligent Vision Systems
Y1 - 2010
A1 - László Gábor Varga
A1 - Péter Balázs
A1 - Antal Nagy
ED - Jacques Blanc-Talon
ED - Don Bone
ED - Wilfried Philips
ED - Dan Popescu
ED - Paul Scheunders
JF - Advanced Concepts for Intelligent Vision Systems
PB - Springer Verlag
CY - Sydney, Australia
N1 - UT: 000287941400037ScopusID: 78650892305doi: 10.1007/978-3-642-17688-3_37
ER -
TY - CHAP
T1 - SITIS 2010: Track SIT editorial message: Signal and Image Technologies
T2 - Proceedings of the 6th International Conference on Signal Image Technology and Internet Based Systems, SITIS 2010
Y1 - 2010
A1 - Albert Dipanda
A1 - Zoltan Kato
ED - Albert Dipanda
ED - Richard Chbeir
ED - Kokou Yetongnon
JF - Proceedings of the 6th International Conference on Signal Image Technology and Internet Based Systems, SITIS 2010
PB - IEEE Computer Society Press
CY - Kuala Lumpur
N1 - ScopusID: 79952549721
ER -
TY - CONF
T1 - Topology preserving 2-subfield 3D thinning algorithms
T2 - Proceedings of the International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA)
Y1 - 2010
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - B Zagar
ED - A Kuijper
ED - H Sahbi
AB - This paper presents a new family of 3D thinning algorithms for extracting skeleton-like shape features (i.e, centerline, medial surface, and topological kernel) from volumetric images. A 2-subfield strategy is applied: all points in a 3D picture are partitioned into two subsets which are alternatively activated. At each iteration, a parallel operator is applied for deleting some border points in the active subfield. The proposed algorithms are derived from Ma's sufficient conditions for topology preservation, and they use various endpoint characterizations.

JF - Proceedings of the International Conference on Signal Processing, Pattern Recognition and Applications (SPPRA)
PB - IASTED ACTA Press
CY - Innsbruck, Austria
N1 - ScopusID: 77954590365
ER -
TY - CHAP
T1 - Topology Preserving 3D Thinning Algorithms using Four and Eight Subfields
T2 - Proceedings of the International Conference on Image Analysis and Recognition (ICIAR)
Y1 - 2010
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Aurélio Campilho
ED - Mohamed Kamel
AB - Thinning is a frequently applied technique for extracting skeleton-like shape features (i.e., centerline, medial surface, and topological kernel) from volumetric binary images. Subfield-based thinning algorithms partition the image into some subsets which are alternatively activated, and some points in the active subfield are deleted. This paper presents a set of new 3D parallel subfield-based thinning algorithms that use four and eight subfields. The three major contributions of this paper are: 1) The deletion rules of the presented algorithms are derived from some sufficient conditions for topology preservation. 2) A novel thinning scheme is proposed that uses iteration-level endpoint checking. 3) Various characterizations of endpoints yield different algorithms. © 2010 Springer-Verlag.

JF - Proceedings of the International Conference on Image Analysis and Recognition (ICIAR)
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Póvoa de Varzim, Portugal
VL - 6111
N1 - ScopusID: 77955432947doi: 10.1007/978-3-642-13772-3_32
JO - LNCS
ER -
TY - CHAP
T1 - Topology Preserving Parallel Smoothing for 3D Binary Images
T2 - Proceedings of the Computational Modeling of Objects Represented in Images (CMORI)
Y1 - 2010
A1 - Gábor Németh
A1 - Péter Kardos
A1 - Kálmán Palágyi
ED - Reneta P Barneva
ED - Valentin E Brimkov
ED - Herbert A Hauptman
ED - Renato M Natal Jorge
ED - João Manuel R S Tavares
AB - This paper presents a new algorithm for smoothing 3D binary images in a topology preserving way. Our algorithm is a reduction operator: some border points that are considered as extremities are removed. The proposed method is composed of two parallel reduction operators. We are to apply our smoothing algorithm as an iteration-by-iteration pruning for reducing the noise sensitivity of 3D parallel surface-thinning algorithms. An efficient implementation of our algorithm is sketched and its topological correctness for (26,6) pictures is proved. © 2010 Springer-Verlag.

JF - Proceedings of the Computational Modeling of Objects Represented in Images (CMORI)
PB - Springer Verlag
CY - Buffalo, USA
VL - 6026
N1 - ScopusID: 77952401887doi: 10.1007/978-3-642-12712-0_26
ER -
TY - CHAP
T1 - Affine alignment of compound objects: A direct approach
T2 - 16th IEEE International Conference on Image Processing (ICIP), 2009
Y1 - 2009
A1 - Csaba Domokos
A1 - Zoltan Kato
AB - A direct approach for parametric estimation of 2D affine deformations between compound shapes is proposed. It provides the result as a least-square solution of a linear system of equations. The basic idea is to fit Gaussian densities over the objects yielding covariant functions, which preserves the effect of the unknown transformation. Based on these functions, linear equations are constructed by integrating nonlinear functions over appropriate domains. The main advantages are: linear complexity, easy implementation, works without any time consuming optimization or established correspondences. Comparative tests show that it outperforms state-of-the-art methods both in terms of precision, robustness and complexity. ©2009 IEEE.

JF - 16th IEEE International Conference on Image Processing (ICIP), 2009
PB - IEEE
CY - Cairo, Egypt
SN - 978-1-4244-5653-6
N1 - UT: 000280464300043ScopusID: 77951939917doi: 10.1109/ICIP.2009.5414195
ER -
TY - COMP
T1 - Affine Registration of Planar Shapes
Y1 - 2009
A1 - Zsolt Katona
A1 - Csaba Domokos
A1 - Zoltan Kato
AB - This is the sample implementation and benchmark dataset of the binary image registration algorithm described in the following paper: Csaba Domokos and Zoltan Kato. Parametric Estimation of Affine Deformations of Planar Shapes. Pattern Recognition, 43(3):569--578, March 2010.

UR - http://www.inf.u-szeged.hu/~kato/software/affbinregdemo.html
ER -
TY - JOUR
T1 - A benchmark set for the reconstruction of hv-convex discrete sets
JF - DISCRETE APPLIED MATHEMATICS
Y1 - 2009
A1 - Péter Balázs
PB - Elsevier
VL - 157
SN - 0166-218X
IS - 16
N1 - UT: 000271375400009ScopusID: 70249142878doi: 10.1016/j.dam.2009.02.019
JO - DISCRETE APPL MATH
ER -
TY - JOUR
T1 - Comparison and evaluation of methods for liver segmentation from CT datasets
JF - IEEE TRANSACTIONS ON MEDICAL IMAGING
Y1 - 2009
A1 - Tobias Heimann
A1 - Brahm Van Ginneken
A1 - Martin A Styner
A1 - Yulia Arzhaeva
A1 - Volker Aurich
A1 - Christian Bauer
A1 - Andreas Beck
A1 - Christoph Becker
A1 - Reinhardt Beichel
A1 - György Bekes
A1 - Fernando Bello
A1 - Gerd Binnig
A1 - Horst Bischof
A1 - Alexander Bornik
A1 - Peter MM Cashman
A1 - Ying Chi
A1 - Andres Córdova
A1 - Benoit M Dawant
A1 - Márta Fidrich
A1 - Jacob D Furst
A1 - Daisuke Furukawa
A1 - Lars Grenacher
A1 - Joachim Hornegger
A1 - Dagmar Kainmüller
A1 - Richard I Kitney
A1 - Hidefumi Kobatake
A1 - Hans Lamecker
A1 - Thomas Lange
A1 - Jeongjin Lee
A1 - Brian Lennon
A1 - Rui Li
A1 - Senhu Li
A1 - Hans-Peter Meinzer
A1 - Gábor Németh
A1 - Daniela S Raicu
A1 - Anne-Mareike Rau
A1 - Eva M Van Rikxoort
A1 - Mikael Rousson
A1 - László Ruskó
A1 - Kinda A Saddi
A1 - Günter Schmidt
A1 - Dieter Seghers
A1 - Akinobi Shimizu
A1 - Pieter Slagmolen
A1 - Erich Sorantin
A1 - Grzegorz Soza
A1 - Ruchaneewan Susomboon
A1 - Jonathan M Waite
A1 - Andreas Wimmer
A1 - Ivo Wolf
AB - This paper presents a comparison study between 10 automatic and six interactive methods for liver segmentation from contrast-enhanced CT images. It is based on results from the "MICCAI 2007 Grand Challenge" workshop, where 16 teams evaluated their algorithms on a common database. A collection of 20 clinical images with reference segmentations was provided to train and tune algorithms in advance. Participants were also allowed to use additional proprietary training data for that purpose. All teams then had to apply their methods to 10 test datasets and submit the obtained results. Employed algorithms include statistical shape models, atlas registration, level-sets, graph-cuts and rule-based systems. All results were compared to reference segmentations five error measures that highlight different aspects of segmentation accuracy. All measures were combined according to a specific scoring system relating the obtained values to human expert variability. In general, interactive methods reached higher average scores than automatic approaches and featured a better consistency of segmentation quality. However, the best automatic methods (mainly based on statistical shape models with some additional free deformation) could compete well on the majority of test images. The study provides an insight in performance of different segmentation approaches under real-world conditions and highlights achievements and limitations of current image analysis techniques. © 2009 IEEE.

CY - Price, K., Anything you can do, I can do better (no you can't) (1986) Comput. Vis. Graph. Image Process, 36 (2-3), pp. 387-391;S. G. Armato, G. McLennan, M. F. McNitt-Gray, C. R. Meyer, D. Yankelevitz, D. R. Aberle, C. I. Henschke, E. A. Hoffman, E. A. Ka
VL - 28
SN - 0278-0062
IS - 8
N1 - ScopusID: 68249121543doi: 10.1109/TMI.2009.2013851
JO - IEEE T MED IMAGING
ER -
TY - JOUR
T1 - Conference of PhD Students in Computer Science
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2009
A1 - Kálmán Palágyi
VL - 19
SN - 0324-721X
IS - 1
JO - ACTA CYBERN-SZEGED
ER -
TY - JOUR
T1 - Detection of Object Motion Regions in Aerial Image Pairs with a Multilayer Markovian Model
JF - IEEE TRANSACTIONS ON IMAGE PROCESSING
Y1 - 2009
A1 - Csaba Benedek
A1 - Tamas Sziranyi
A1 - Zoltan Kato
A1 - Josiane Zerubia
AB - We propose a new Bayesian method for detectingthe regions of object displacements in aerial image pairs. We use a robust but coarse 2-D image registration algorithm. Our main challenge is to eliminate the registration errors from the extracted change map. We introduce a three-layer Markov Random Field (L3MRF) model which integrates information from two different features, and ensures connected homogenous regions in the segmented images. Validation is given on real aerial photos.

PB - IEEE
VL - 18
SN - 1057-7149
IS - 10
N1 - UT: 000269715500013ScopusID: 70349442338doi: 10.1109/TIP.2009.2025808
JO - IEEE T IMAGE PROCESS
ER -
TY - JOUR
T1 - Emissziós Diszkrét Tomográfiai Módszerek Alkalmazása Faktorstruktúrákra.
JF - ALKALMAZOTT MATEMATIKAI LAPOK
Y1 - 2009
A1 - Antal Nagy
VL - 26
SN - 0133-3399
JO - ALKALMAZOTT MATEMATIKAI LAPOK
ER -
TY - CHAP
T1 - An evolutionary approach for object-based image reconstruction using learnt priors
T2 - Image Analysis
Y1 - 2009
A1 - Péter Balázs
A1 - Mihály Gara
ED - Arnt-Borre Salberg
ED - Jon Yngve Hardeberg
ED - Robert Jenssen
AB - In this paper we present a novel algorithm for reconstructingbinary images containing objects which can be described by some parameters. In particular, we investigate the problem of reconstructing binary images representing disks from four projections. We develop a genetic algorithm for this and similar problems. We also discuss how prior information on the number of disks can be incorporated into the reconstruction in order to obtain more accurate images. In addition, we present a method to exploit such kind of knowledge from the projections themselves. Experiments on artificial data are also conducted. © 2009 Springer Berlin Heidelberg.

JF - Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer-Verlag
CY - Oslo, Norway
SN - 978-3-642-02229-6
N1 - UT: 000268661000053ScopusID: 70350650400doi: 10.1007/978-3-642-02230-2_53
JO - LNCS
ER -
TY - CHAP
T1 - Fully Parallel 3D Thinning Algorithms based on Sufficient Conditions for Topology Preservation
T2 - Proceedings of Discrete Geometry for Computer Imagery (DGCI)
Y1 - 2009
A1 - Kálmán Palágyi
A1 - Gábor Németh
ED - Srecko Brlek
ED - Christophe Reutenauer
ED - Xavier Provençal
AB - This paper presents a family of parallel thinning algorithms for extracting medial surfaces from 3D binary pictures. The proposed algorithms are based on sufficient conditions for 3D parallel reduction operators to preserve topology for (26,6) pictures. Hence it is self-evident that our algorithms are topology preserving. Their efficient implementation on conventional sequential computers is also presented. © 2009 Springer Berlin Heidelberg.

JF - Proceedings of Discrete Geometry for Computer Imagery (DGCI)
PB - Springer Verlag
CY - Montreal, Quebec, Canada
SN - 978-3-642-04396-3
N1 - ScopusID: 77952414581doi: 10.1007/978-3-642-04397-0_41
ER -
TY - CHAP
T1 - A Graph Based Data Model for Graphics Interpretation
T2 - Graph-Based Representations in Pattern Recognition
Y1 - 2009
A1 - Endre Katona
JF - Graph-Based Representations in Pattern Recognition
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Venice, Italy
VL - 5534
ER -
TY - JOUR
T1 - A higher-order active contour model of a 'gas of circles' and its application to tree crown extraction
JF - PATTERN RECOGNITION
Y1 - 2009
A1 - Peter Horvath
A1 - Ian Jermyn
A1 - Zoltan Kato
A1 - Josiane Zerubia
VL - 42
SN - 0031-3203
IS - 5
N1 - UT: 000263431200011doi: 10.1016/j.patcog.2008.09.008
JO - PATTERN RECOGN
ER -
TY - JOUR
T1 - Learning connectedness and convexity of binary images from their projections
JF - PURE MATHEMATICS AND APPLICATIONS
Y1 - 2009
A1 - Mihály Gara
A1 - Tamás Sámuel Tasi
A1 - Péter Balázs
VL - 20
SN - 1218-4586
IS - 1-2
JO - PU.M.A PURE MATH APPL
ER -
TY - CHAP
T1 - A Markov random field model for extracting near-circular shapes
T2 - 16th IEEE International Conference on Image Processing (ICIP)
Y1 - 2009
A1 - Tamás Blaskovics
A1 - Zoltan Kato
A1 - Ian Jermyn
AB - We propose a binary Markov Random Field (MRF) model that assigns high probability to regions in the image domain consisting of an unknown number of circles of a given radius. We construct the model by discretizing the 'gas of circles' phase field model in a principled way, thereby creating an 'equivalent'MRF. The behaviour of the resultingMRF model is analyzed, and the performance of the new model is demonstrated on various synthetic images as well as on the problem of tree crown detection in aerial images. ©2009 IEEE.

JF - 16th IEEE International Conference on Image Processing (ICIP)
PB - IEEE
CY - Cairo, Egypt
SN - 978-1-4244-5653-6
N1 - UT: 000280464300268ScopusID: 77951945383doi: 10.1109/ICIP.2009.5413472
ER -
TY - PAT
T1 - Method and system for automatically segmenting organs from three dimensional computed tomography images
Y1 - 2009
A1 - Márta Fidrich
A1 - Eörs Máté
A1 - László Gábor Nyúl
A1 - Attila Kuba
A1 - Bence Kiss
CY - Amerikai Egyesült Államok
VL - US20050907690
IS - US7545979
ER -
TY - BOOK
T1 - MIPPR 2009: Multispectral Image Acquisition and Processing
Y1 - 2009
ED - Jayaram K Udupa
ED - Nong Sang
ED - László Gábor Nyúl
ED - Hengqing Tong
PB - SPIE
CY - Bellingham; Washington
VL - 7494
SN - 9780819478054
N1 - doi: 10.1117/12.839775Yichang
ER -
TY - JOUR
T1 - Multimodal Automated Glaucoma Detection Combining the Glaucoma Probability Score and the Glaucoma Risk Index
JF - INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
Y1 - 2009
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
A1 - Georg Michelson
AB - Purpose:Fundus camera and Heidelberg Retina Tomograph (HRT) arecommonly used for reliable glaucoma diagnosis. Quantitative glaucoma scores, however, do not utilize both image content simultaneously. We propose the combination of topography and fundus image based indices for automated glaucoma detection which outperforms their sole application of either. Methods:The probabilistic values of topography based Glaucoma Probability Score (GPS) and our fundus image based Glaucoma Risk Index (GRI) are assembled to a two-dimensional feature space. In contrast to established methods the subsequent application of a probabilistic nu-Support Vector Machine classifier (nu = 0.5, kernel: radial basis function) uses both the topographic and the textural information to determine a final glaucoma probability. Instances labeled with a final probability greater than 0.5 are considered glaucomatous.For the evaluations in a 10-fold cross- validation setup, we took a sample set (mean age: 55.4 ± 10.9 years) of papilla images of 149 glaucomatous patients (FDT test time 67.4 ± 35.6 s) and 246 normals from the Erlangen Glaucoma Registry. The gold standard diagnosis was given by a glaucoma specialist based on an elaborate ophthalmological examination with ophthalmoscopy, visual field, IOP, FDT, and HRT II. The GPS was calculated by HRT device while papilla centered color fundus images (Kowa non-myd, FOV 22°) were used to calculate the GRI. Results:The classification of the GRI resulted in an area under ROC curve (AUC) of 0.81 with an F-measure of 0.71 for glaucomatous cases and 0.83 for normals. The GPS achieved an AUC of 0.86 while the F-measure for glaucoma was 0.74 (F-measure for healthy was 0.84).The combination of both indices clearly increased the AUC by 4% up to 0.9 compared to the sole application of the GPS. The F-measure for glaucomatous images was improved up to 0.76 (F-measure for healthy images was 0.86). Conclusions:The proposed combination of the topography based GPS and the fundus image based GRI shows superior performance compared to either index alone.Both indices utilize complementary information about the glaucoma disease. Consequently, this multimodal combined application of both indices is promising to reach a more reliable automated glaucoma detection performance. The approach can be used in large screening applications where an automated tool is essential to support the experts in finding glaucomatous eyes.

VL - 50
SN - 0146-0404
IS - 5
N1 - ARVO Meeting Abstracts
JO - INVEST OPHTH VIS SCI
ER -
TY - CONF
T1 - Nonlinear registration of binary shapes
T2 - 16th IEEE International Conference on Image Processing (ICIP)
Y1 - 2009
A1 - Jozsef Nemeth
A1 - Csaba Domokos
A1 - Zoltan Kato
AB - A novel approach is proposed to estimate the parameters of a diffeomorphism that aligns two binary images. Classical approaches usually define a cost function based on a similarity metric and then find the solution via optimization. Herein, we trace back the problem to the solution of a system of non-linear equations which directly provides the parameters of the aligning transformation. The proposed method works without any time consuming optimization step or established correspondences. The advantage of our algorithm is that it is easy to implement, less sensitive to the strength of the deformation, and robust against segmentation errors. The efficiency of the proposed approach has been demonstrated on a large synthetic dataset as well as in the context of an industrial application. ©2009 IEEE.

JF - 16th IEEE International Conference on Image Processing (ICIP)
PB - IEEE
CY - Cairo, Egypt
SN - 978-1-4244-5653-6
N1 - UT: 000280464300275ScopusID: 77951946286doi: 10.1109/ICIP.2009.5413468
ER -
TY - CHAP
T1 - Object subsampling strategies to improve computational performance
T2 - Proceedings of the 6th International Symposium on Image and Signal Processing and Analysis
Y1 - 2009
A1 - András Hajdú
A1 - Péter Veres
A1 - Attila Tanacs
A1 - Rorland Harangozó
ED - P Zinterhof
ED - Sven Lončarić
ED - A Uhl
ED - Alberto Carini
AB - We investigate object simplification methods based on Centroidal Voronoi Tesselation (CVT) that share the possibility of great speed-ups in various scenarios. We propose Constrained CVT to sample points from the object boundary and the Region-based CVT to be able to subsample lower dimensional objects, as well. Moreover we introduce custom weight functions based on object properties. Thus, wecan be more specific on what are the important parts of the subsampled object. We also list several novel applications corresponding to the theoretical achivements presented. The advantages of applying the subsampling strategies are presented for registration, human detection, and the segmentation of the retinal vascular system, respectively. Quantitative results are shown to check the deterioration of the accuracy with the level of subsampling, and the computational gain. We also make comparisons with other naive (e.g. random) subsampling methods.

JF - Proceedings of the 6th International Symposium on Image and Signal Processing and Analysis
PB - IEEE Press
CY - Salzburg
N1 - ScopusID: 70450253246
ER -
TY - CHAP
T1 - An order-independent sequential thinning algorithm
T2 - Proceedings of the International Workshop on Combinatorial Image Analysis (IWCIA)
Y1 - 2009
A1 - Péter Kardos
A1 - Gábor Németh
A1 - Kálmán Palágyi
ED - Petra Wiederhold
ED - Reneta P Barneva
AB - Thinning is a widely used approach for skeletonization. Sequential thinning algorithms use contour tracking: they scan border points and remove the actual one if it is not designated a skeletal point. They may produce various skeletons for different visiting orders. In this paper, we present a new 2-dimensional sequential thinning algorithm, which produces the same result for arbitrary visiting orders and it is capable of extracting maximally thinned skeletons. © Springer-Verlag Berlin Heidelberg 2009.

JF - Proceedings of the International Workshop on Combinatorial Image Analysis (IWCIA)
PB - Springer Verlag
CY - Playa del Carmen, Mexico
SN - 978-3-642-10208-0
UR - http://link.springer.com/chapter/10.1007/978-3-642-10210-3_13
N1 - ScopusID: 78650496028doi: 10.1007/978-3-642-10210-3_13
ER -
TY - CHAP
T1 - Reconstruction of canonical hv-convex discrete sets from horizontal and vertical projections
T2 - Combinatorial Image Analysis
Y1 - 2009
A1 - Péter Balázs
ED - Petra Wiederhold
ED - Reneta P Barneva
AB - The problem of reconstructing some special hv-convex discretesets from their two orthogonal projections is considered. In general, the problem is known to be NP-hard, but it is solvable in polynomial time if the discrete set to be reconstructed is also 8-connected. In this paper, we define an intermediate class - the class of hv-convex canonical discrete sets - and give a constructive proof that the above problem remains computationally tractable for this class, too. We also discuss some further theoretical consequences and present experimental results as well. © Springer-Verlag Berlin Heidelberg 2009.

JF - Combinatorial Image Analysis
PB - Springer Verlag
CY - Berlin; Heidelberg; New York; London; Paris; Tokyo
SN - 978-3-642-10208-0
N1 - UT: 000279344100022ScopusID: 78650444641doi: 10.1007/978-3-642-10210-3_22
ER -
TY - CHAP
T1 - Recovering affine deformations of fuzzy shapes
T2 - Image Analysis
Y1 - 2009
A1 - Attila Tanacs
A1 - Csaba Domokos
A1 - Nataša Sladoje
A1 - Joakim Lindblad
A1 - Zoltan Kato
ED - Arnt-Borre Salberg
ED - Jon Yngve Hardeberg
ED - Robert Jenssen
AB - Fuzzy sets and fuzzy techniques are attracting increasing attention nowadays in the field of image processing and analysis. It has been shown that the information preserved by using fuzzy representation based on area coverage may be successfully utilized to improve precision and accuracy of several shape descriptors; geometric moments of a shape are among them. We propose to extend an existing binary shape matching method to take advantage of fuzzy object representation. The result of a synthetic test show that fuzzy representation yields smaller registration errors in average. A segmentation method is also presented to generate fuzzy segmentations of real images. The applicability of the proposed methods is demonstrated on real X-ray images of hip replacement implants. © 2009 Springer Berlin Heidelberg.

JF - Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer-Verlag
CY - Oslo, Norway
N1 - UT: 000268661000075ScopusID: 70350676212doi: 10.1007/978-3-642-02230-2_75
JO - LNCS
ER -
TY - CHAP
T1 - Retinal image analysis for automated glaucoma risk evaluation
T2 - MIPPR 2009: Medical Imaging, Parallel Processing of Images, and Optimization Techniques
Y1 - 2009
A1 - László Gábor Nyúl
ED - Jianguo Liu
ED - Kunio Doi
ED - Aaron Fenster
ED - C S Chan
AB - Images of the eye ground not only provide an insight toimportant parts of the visual system but also reflect the general state of health of the entire human body. Automatic retina image analysis is becoming an important screening tool for early detection of certain risks and diseases. Glaucoma is one of the most common causes of blindness and is becoming even more important considering the ageing society. Robust mass-screening may help to extend the symptom-free life of affected patients. Our research is focused on a novel automated classification system for glaucoma, based on image features from fundus photographs. Our new data-driven approach requires no manual assistance and does not depend on explicit structure segmentation and measurements. First, disease independent variations, such as nonuniform illumination, size differences, and blood vessels are eliminated from the images. Then, the extracted high-dimensional feature vectors are compressed via PCA and combined before classification with SVMs takes place. The technique achieves an accuracy of detecting glaucomatous retina fundus images comparable to that of human experts. The “vessel- free” images and intermediate output of the methods are novel representations of the data for the physicians that may provide new insight into and help to better understand glaucoma.

JF - MIPPR 2009: Medical Imaging, Parallel Processing of Images, and Optimization Techniques
PB - SPIE
CY - Bellingham; Washington
N1 - ScopusID: 71549165160doi: 10.1117/12.851179
ER -
TY - CONF
T1 - Semi-automatic bone fracture reduction in surgical planning
T2 - International Conference on Computer Assisted Radiology and Surgery (CARS)
Y1 - 2009
A1 - Balázs Erdőhelyi
A1 - Endre Varga
AB - The surgical intervention of complex bone fractures has to be planned very carefully, especially for such a complex region as the pelvic ring. The computer aided surgical planning is done before the actual surgery takes place and its main purpose is to gather more information about the dislocation of the bone fragments and to arrange the surgical implants to be inserted. With the help of finite element analysis even the biomechanical stability of the whole plan can be predicted. To create such a plan the following steps are performed. First, the CT dataset of the patient is segmented [1], which enables us to treat the different bones and broken fragments separately. Next the surface of this volumetric dataset is determined [2] and presented in a 3D environment. Since the fragments may have moved during the fracture, it is essential to move and rotate them back to their original anatomic position. Without this reduction, no implants can be inserted, since the final locations of the fragments are unknown. Previous solutions to the fracture reduction problem included moving the fragments with the mouse, or a special 3D haptic device. The former is not intuitive to use since the mouse is only 2D, and the later is expensive and still requires learning. ` `

JF - International Conference on Computer Assisted Radiology and Surgery (CARS)
PB - Springer Verlag
CY - Berlin, Germany
VL - 4
ER -
TY - ABST
T1 - Supervised Color Image Segmentation in a Markovian Framework
Y1 - 2009
A1 - Mihály Gara
A1 - Zoltan Kato
AB - This is the sample implementation of a Markov random field based color image segmentation algorithm described in the following paper: Zoltan Kato, Ting Chuen Pong, and John Chung Mong Lee. Color Image Segmentation and Parameter Estimation in a Markovian Framework. Pattern Recognition Letters, 22(3-4):309--321, March 2001. Note that the current demo program implements only a supervised version of the segmentation method described in the above paper (i.e. parameter values are learned interactively from representative regions selected by the user). Otherwise, the program implements exactly the color MRF model proposed in the paper. Images are automatically converted from RGB to the perceptually uniform CIE-L*u*v* color space before segmentation.

UR - http://www.inf.u-szeged.hu/~kato/software/colormrfdemo.html
ER -
TY - ABST
T1 - VCP volar approach
Y1 - 2009
A1 - Endre Varga
A1 - Balázs Erdőhelyi
ER -
TY - JOUR
T1 - A 3D fully parallel surface-thinning algorithm
JF - THEORETICAL COMPUTER SCIENCE
Y1 - 2008
A1 - Kálmán Palágyi
AB - The thinning is an iterative layer by layer erosion until only the "skeletons" of the objects are left. This paper presents a thinning algorithm for extracting medial surfaces from 3D binary pictures. The strategy which is used is called fully parallel, which means that the same parallel operator is applied at each iteration. An efficient implementation of the proposed algorithm on conventional sequential computers is given and the topological correctness for (26, 6) binary pictures is proved. © 2008 Elsevier B.V. All rights reserved.

PB - Elsevier
CY - AHUJA N, 1997, IEEE T PATTERN ANAL, V19, P169ARCELLI C, 2006, LECT NOTES COMPUT SC, V4245, P555BERTRAND G, 1994, P SPIE C VISION GEOM, V2356, P113BERTRAND G, 1995, CR ACAD SCI I-MATH, V321, P1077BERTRAND G, 1995, P 5 INT C DISCR GEOM, P233BERTRAND G,
VL - 406
SN - 0304-3975
IS - 1-2
N1 - UT: 000260289400014ScopusID: 51749087902doi: 10.1016/j.tcs.2008.06.041
JO - THEOR COMPUT SCI
ER -
TY - JOUR
T1 - Algorithms, automata, complexity and games Preface
JF - THEORETICAL COMPUTER SCIENCE
Y1 - 2008
A1 - Joost K Batenburg
A1 - Antal Nagy
A1 - Maurice Nivat
VL - 406
SN - 0304-3975
IS - 1-2
N1 - UT: 000260289400001doi: 10.1016/j.tcs.2008.07.010
JO - THEOR COMPUT SCI
ER -
TY - JOUR
T1 - On the ambiguity of reconstructing hv-convex binary matrices with decomposable configurations
JF - ACTA CYBERNETICA-SZEGED
Y1 - 2008
A1 - Péter Balázs
AB - `Reconstructing binary matrices from their row, column, diagonal, and antidiagonal sums (also called projections) plays a central role in discrete tomography. One of the main difficulties in this task is that in certain cases the projections do not uniquely determine the binary matrix. This can yield an extremely large number of (sometimes very different) solutions. This ambiguity can be reduced by having some prior knowledge about the matrix to be reconstructed. The main challenge here is to find classes of binary matrices where ambiguity is drastically reduced or even completely eliminated. The goal of this paper is to study the class of $hv$-convex matrices which have decomposable configurations from the viewpoint of ambiguity. First, we give a negative result in the case of three projections. Then, we present a heuristic for the reconstruction using four projections and analyze its performance in quality and running time.`

PB - University of Szeged
CY - Szeged, Hungary
VL - 18
SN - 0324-721X
IS - 3
N1 - ScopusID: 47749139604
JO - ACTA CYBERN-SZEGED
ER -
TY - JOUR
T1 - Automated Glaucoma Detection From Color Fundus Photographs
JF - INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
Y1 - 2008
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
A1 - Georg Michelson
AB - Purpose:The presentation of a novel fully automated system thatseparates glaucomatous from healthy cases based on digital fundus images. Methods:A pre-processing step eliminates certain disease independent variations such as illumination inhomogeneities, papilla size differences and vessel structures from the input images. In order to characterize glaucomatous changes, generic feature types (pixel intensities, frequency coefficients, histogram parameters, Gabor textures, spline coefficients) are extracted. In contrast to existing approaches, each feature vector is compressed by Principal Component Analysis. The classification of the transformed features is done by a state- of-the-art nu-Support Vector Machine.For the elaborate experimental evaluation of the proposed system architecture we took a large set of papilla-centered color fundus images of 100 glaucoma patients (FDT test time 67.25 ± 33.4 s) and 100 normals (overall mean age 57.0 ± 10.0 years) from the Erlangen Glaucoma Registry (Kowa non-myd, FOV 22,5°). The gold standard was given by an experienced ophthalmologist based on a complete ophthalmological examination with ophthalmoscopy, visual field, IOP, FDT, and HRT II. Results:Classification of compressed raw pixel intensities gained a success rate of 83% with a specificity of 0.72 and a sensitivity of 0.94 to detect glaucomatous cases. A success rate of 86% was achieved by using spline coefficients with a specificity of 0.78 and a sensitivity of 0.94 to detect glaucoma. The combination of both features slightly increased specificity to 0.82 (sensitivity = 0.92). The kappa statistic of 0.74 states a robust classification scheme. Conclusions:The proposed algorithm achieves a robust and competitive glaucoma detection rate. It is comparable to known methods applied to topographic papilla images and does not depend on segmentation-based measurements. For the first time, automated glaucoma detection is performed on color fundus images. Thus, fundus photography is an appropriate modality for computer-assisted glaucoma screening.

VL - 49
SN - 0146-0404
IS - 5
N1 - ARVO Meeting Abstracts
JO - INVEST OPHTH VIS SCI
ER -
TY - CHAP
T1 - Binary image registration using covariant gaussian densities
T2 - Image Analysis and Recognition
Y1 - 2008
A1 - Csaba Domokos
A1 - Zoltan Kato
ED - Aurélio Campilho
AB - We consider the estimation of 2D affine transformations aligning a known binary shape and its distorted observation. The classical way to solve this registration problem is to find correspondences between the two images and then compute the transformation parameters from these landmarks. In this paper, we propose a novel approach where the exact transformation is obtained as a least-squares solution of a linear system. The basic idea is to fit a Gaussian density to the shapes which preserves the effect of the unknown transformation. It can also be regarded as a consistent coloring of the shapes yielding two rich functions defined over the two shapes to be matched. The advantage of the proposed solution is that it is fast, easy to implement, works without established correspondences and provides a unique and exact solution regardless of the magnitude of transformation. © 2008 Springer-Verlag Berlin Heidelberg.

JF - Image Analysis and Recognition
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Póvoa de Varzim, Portugal
SN - 978-3-540-69811-1
N1 - UT: 000257302500045ScopusID: 47749098390doi: 10.1007/978-3-540-69812-8_45
JO - LNCS
ER -
TY - CONF
T1 - Comparison Radiography and Tomography Possibilities of FRM-II (20 MW) and Budapest (10 MW) Research Reactor
T2 - Proceedings of the Eight World Conference WCNR-8
Y1 - 2008
A1 - Márton Balaskó
A1 - Attila Kuba
A1 - Attila Tanacs
A1 - Zoltán Kiss
A1 - Antal Nagy
A1 - Burkhard Schillinger
ED - Muhammed Arif
JF - Proceedings of the Eight World Conference WCNR-8
ER -
TY - CHAP
T1 - Decision trees in binary tomography for supporting the reconstruction of hv-convex connected images
T2 - Proceedings of the Advanced Concepts for Intelligent Vision Systems
Y1 - 2008
A1 - Péter Balázs
A1 - Mihály Gara
AB - In binary tomography, several algorithms are known for reconstructing binary images having some geometrical properties from their projections. In order to choose the appropriate reconstruction algorithm it is necessary to have a priori information of the image to be reconstructed. In this way we can improve the speed and reduce the ambiguity of the reconstruction. Our work is concerned with the problem of retrieving geometrical information from the projections themselves. We investigate whether it is possible to determine geometric features of binary images if only their projections are known. Most of the reconstruction algorithms based on geometrical information suppose $hv$-convexity or connectedness about the image to be reconstructed. We investigate those properties in detail, and also the task of separating 4- and 8-connected images. We suggest decision trees for the classification, and show some preliminary experimental results of applying them for the class of $hv$-convex and connected discrete sets. ` `

JF - Proceedings of the Advanced Concepts for Intelligent Vision Systems
T3 - Lecture Notes in Computer Science
PB - Springer
CY - Juan-les-Pins, France
VL - 5259
JO - LNCS
ER -
TY - CONF
T1 - Determination of geometric features of binary images from their projections by using decision trees
T2 - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
Y1 - 2008
A1 - Mihály Gara
A1 - Péter Balázs
ED - Kálmán Palágyi
ED - Balázs Bánhelyi
ED - Tamás Gergely
ED - István Matievics
JF - Conference of PhD Students in Computer Science. Volume of Extended Abstracts
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - JOUR
T1 - Discrete tomographic reconstruction of binary images with disjoint components using shape information
JF - INTERNATIONAL JOURNAL OF SHAPE MODELLING
Y1 - 2008
A1 - Péter Balázs
AB - We present a general framework for reconstructing binary images with disjoint components from the horizontal and vertical projections. We develop a backtracking algorithm that works for binary images having components from an arbitrary class. Thus, a priori knowledge about the components of the image to be reconstructed can be incorporated into the reconstruction process. In addition, we show how to extend the algorithm to obtain a branch-and-bound scheme useful to reconstruct images satisfying some further properties (for example similarity to a model image) as much as possible. Experimental results are also presented.

PB - World Scientific
VL - 14
SN - 0218-6543
IS - 2
N1 - ScopusID: 76849116810doi: 10.1142/S0218654308001142
JO - INT J SHAPE MODEL
ER -
TY - JOUR
T1 - The Erlanger Glaucoma Matrix - A Visualization Approach Towards Optimal Glaucomatous Optic Nerve Head Image Presentation
JF - INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
Y1 - 2008
A1 - Jörg Meier
A1 - Rudriger Bock
A1 - C Forman
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
A1 - Georg Michelson
AB - Purpose:Presentation of a two-dimensional visualization approachfor intuitive and reliable glaucoma diagnosis and for setting a current observation into a relationship with pre-diagnosed data. Methods:We present a new matrix visualization technique for digital optic nerve head images. The matrix is filled with 300 pre-diagnosed reference images which show different papilla sizes and varying stages of glaucoma disease. In matrix rows the samples range from healthy ones to advanced glaucoma cases. In matrix columns the papillas are ordered by the size of the optic nerve head. The approach generalizes such that the samples can be ordered by additional criteria, too, e. g. subjects' age or anamnestic risk factors. Furthermore arbitrary image modalities and image numbers can be incorporated. Results:The glaucoma classification of a single image is difficult even for experts. Our proposed visualization provides an intuitive way for neighborhood comparisons of optic nerve head images. It allows to evaluate an image in the context of given pre-diagnosed reference samples. By the two-dimensional presentation one can study disease-dependent changes separate from other variations. Glaucoma progression can be observed separated from size variations. Thus, it supports diagnosis even in problematic cases such as macropapillas. The trustworthiness of physicians' diagnosis can be improved. Conclusions:Our approach gives insights on glaucomatous optic nerve appearance in relation to varying papilla sizes. The novel visualization of a single image within the context of other images is considered as an important tool for learning and training medical glaucoma detection. This approach visualizes computer calculated risk estimations by presenting the result within context of given gold-standard images. In contrast to pure classification systems our method does not come up with a hard decision but explains the relationship to similar pre- diagnosed cases.

PB - Arvo
VL - 49
SN - 0146-0404
IS - 5
N1 - ARVO Meeting Abstracts
JO - INVEST OPHTH VIS SCI
ER -
TY - JOUR
T1 - Finite element analysis of mandible virtual model
JF - JOURNAL OF CRANIO-MAXILLOFACIAL SURGERY
Y1 - 2008
A1 - Endre Varga
A1 - Zoltán Raskó
A1 - Balázs Erdőhelyi
A1 - L Seres
A1 - J Piffko
PB - Elsevier
VL - 36
SN - 1010-5182
IS - Suppl 1
N1 - doi: 10.1016/S1010-5182(08)71931-0
JO - J CRANIO MAXILL SURG
ER -
TY - JOUR
T1 - A framework for generating some discrete sets with disjoint components by using uniform distributions
JF - THEORETICAL COMPUTER SCIENCE
Y1 - 2008
A1 - Péter Balázs
PB - Elsevier
VL - 406
SN - 0304-3975
IS - 1-2
N1 - UT: 000260289400004ScopusID: 51549107301doi: 10.1016/j.tcs.2008.06.010
JO - THEOR COMPUT SCI
ER -
TY - JOUR
T1 - Geometrical model-based segmentation of the organs of sight on CT images
JF - MEDICAL PHYSICS
Y1 - 2008
A1 - György Bekes
A1 - Eörs Máté
A1 - László Gábor Nyúl
A1 - Attila Kuba
A1 - Márta Fidrich
AB - Segmentation of organs of sight such as the eyeballs, lenses,and optic nerves is a time consuming task for clinicians. The small size of the organs and the similar density of the surrounding tissues make the segmentation difficult. We developed a new algorithm to segment these organs with minimal user interaction. The algorithm needs only three seed points to fit an initial geometrical model to start an effective segmentation. The clinical evaluation shows that the output of our method is useful in clinical practice.

VL - 35
SN - 0094-2405
IS - 2
N1 - UT: 000253318400036ScopusID: 38849194643doi: 10.1118/1.2826557
JO - MED PHYS
ER -
TY - JOUR
T1 - In Memoriam Attila Kuba (1953-2006)
JF - THEORETICAL COMPUTER SCIENCE
Y1 - 2008
A1 - Joost K Batenburg
A1 - Antal Nagy
A1 - Maurice Nivat
CY - KUBA A, PUBLICATION LIST
VL - 406
SN - 0304-3975
IS - 1-2
N1 - UT: 000260289400002doi: 10.1016/j.tcs.2008.07.011
JO - THEOR COMPUT SCI
ER -
TY - CHAP
T1 - Novel Visualization Approach of an Automated Image Based Glaucoma Risk Index for Intuitive Diagnosis
T2 - Analysis of Biomedical Signals and Images
Y1 - 2008
A1 - Jörg Meier
A1 - Rudriger Bock
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
A1 - Georg Michelson
ED - Jiří Jan
ED - Jiří Konzuplik
ED - Ivo Provazník
AB - Glaucoma is one of the most common causes for blindnessworldwide. Screening is adequate to detect glaucoma at an early stage. Although it is supported by computer assisted tools no further information from former clinical studies is incorporated. We devised a novel visualization tool that presents additional comparative image data for the diagnosis process. Automated computation of a glaucoma risk index on color fundus photographs is used to initially position an undiagnosed image in reference data. The index achieves a competitive glaucoma detection rate. The combination of the automated risk index and the new visualization technique is an important tool towards a faster and more reliable diagnosis of glaucoma.

JF - Analysis of Biomedical Signals and Images
PB - Brno University of Technology
CY - Brno
N1 - WoS: 000303717200044
ER -
TY - CHAP
T1 - On the number of hv-convex discrete sets
T2 - Combinatorial Image Analysis
Y1 - 2008
A1 - Péter Balázs
ED - Valentin E Brimkov
ED - Reneta P Barneva
ED - Herbert A Hauptman
AB - One of the basic problems in discrete tomography is thereconstruction of discrete sets from few projections. Assuming that the set to be reconstructed fulfills some geometrical properties is a commonly used technique to reduce the number of possibly many different solutions of the same reconstruction problem. The class of hv-convex discrete sets and its subclasses have a well-developed theory. Several reconstruction algorithms as well as some complexity results are known for those classes. The key to achieve polynomial-time reconstruction of an hv- convex discrete set is to have the additional assumption that the set is connected as well. This paper collects several statistics on hv-convex discrete sets, which are of great importance in the analysis of algorithms for reconstructing such kind of discrete sets. © 2008 Springer-Verlag Berlin Heidelberg.

JF - Combinatorial Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Buffalo, NY, USA
SN - 978-3-540-78274-2
N1 - UT: 000254600100010ScopusID: 70249110264doi: 10.1007/978-3-540-78275-9_10
JO - LNCS
ER -
TY - CHAP
T1 - Parametric estimation of affine deformations of binary images
T2 - Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Y1 - 2008
A1 - Csaba Domokos
A1 - Zoltan Kato
A1 - Joseph M Francos
AB - We consider the problem of planar object registration on binary images where the aligning transformation is restricted to the group of affine transformations. Previous approaches usually require established correspondences or the solution of nonlinear optimization problems. Herein we show that it is possible to formulate the problem as the solution of a system of up to third order polynomial equations. These equations are constructed in a simple way using some basic geometric information of binary images. It does not need established correspondences nor the solution of complex optimization problems. The resulting algorithm is fast and provides a direct solution regardless of the magnitude of transformation. ©2008 IEEE.

JF - Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
PB - IEEE
CY - Las Vegas, NV, USA
SN - 978-1-4244-1483-3
N1 - UT: 000257456700223ScopusID: 51449098982doi: 10.1109/ICASSP.2008.4517753
ER -
TY - CHAP
T1 - Reconstruction of binary images with few disjoint components from two projections
T2 - Advances in Visual Computing
Y1 - 2008
A1 - Péter Balázs
ED - George Bebis
ED - Richard Boyle
ED - Bahram Parvin
ED - Darko Koracin
ED - Paolo Remagnino
ED - Fatih Porikli
ED - Jörg Peters
ED - James Klosowski
ED - Laura Arns
ED - Yu Ka Chun
ED - Theresa-Marie Rhyne
ED - Laura Monroe
AB - We present a general framework for reconstructing binary imageswith few disjoint components from the horizontal and vertical projections. We develop a backtracking algorithm that works for binary images having components from an arbitrary class. Thus, a priori information about the components of the image to be reconstructed can be incorporated into the reconstruction process. In addition, we can keep control over the number of components which can increase the speed and accuracy of the reconstruction. Experimental results are also presented. © 2008 Springer Berlin Heidelberg.

JF - Advances in Visual Computing
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Las Vegas, NV, USA
SN - 978-3-540-89645-6
N1 - UT: 000262709700114ScopusID: 70149090157doi: 10.1007/978-3-540-89646-3_114
JO - LNCS
ER -
TY - JOUR
T1 - Segmentation of color images via reversible jump MCMC sampling
JF - IMAGE AND VISION COMPUTING
Y1 - 2008
A1 - Zoltan Kato
PB - Elsevier
VL - 26
SN - 0262-8856
IS - 3
N1 - UT: 000252196500005doi: 10.1016/j.imavis.2006.12.004
JO - IMAGE VISION COMPUT
ER -
TY - CHAP
T1 - Skeletonization based on metrical neighborhood sequences
T2 - Computer Vision Systems
Y1 - 2008
A1 - Attila Fazekas
A1 - Kálmán Palágyi
A1 - György Kovács
A1 - Gábor Németh
ED - Antonios Gasteratos
ED - Markus Vincze
ED - John K Tsotsos
AB - Skeleton is a shape descriptor which summarizes the general formof objects. It can be expressed in terms of the fundamental morphological operations. The limitation of that characterization is that its construction based on digital disks such that cannot provide good approximation to the Euclidean disks. In this paper we define a new type of skeleton based on neighborhood sequences that is much closer to the Euclidean skeleton. A novel method for quantitative comparison of skeletonization algorithms is also proposed. © 2008 Springer- Verlag Berlin Heidelberg.

JF - Computer Vision Systems
PB - Springer Verlag
CY - Santorini, Greece
SN - 978-3-540-79546-9
N1 - ScopusID: 44649159529doi: 10.1007/978-3-540-79547-6
ER -
TY - CONF
T1 - Study of the Inner Structure of a Damaged Control Rod by Neutron and X-ray Radiography and Discrete Tomography
T2 - Proceedings of the Eight World Conference WCNR-8
Y1 - 2008
A1 - Márton Balaskó
A1 - Erzsébet Sváb
A1 - Zoltán Kiss
A1 - Attila Tanacs
A1 - Antal Nagy
A1 - Attila Kuba
ED - Muhammed Arif
JF - Proceedings of the Eight World Conference WCNR-8
ER -
TY - PAT
T1 - Systems and methods for segmenting an organ in a plurality of images
Y1 - 2008
A1 - Márta Fidrich
A1 - Géza Makay
A1 - Eörs Máté
A1 - Emese Balogh
A1 - Attila Kuba
A1 - László Gábor Nyúl
A1 - Judit Kanyó
CY - Amerikai Egyesült Államok
VL - US20040858241
IS - US7388973
ER -
TY - CHAP
T1 - Techniques of Virtual Dissection of the Colon Based on Spiral CT Data
T2 - Image Processing in Radiology
Y1 - 2008
A1 - Erich Sorantin
A1 - Emese Balogh
A1 - Anna Vilanova Bartroli
A1 - Kálmán Palágyi
A1 - László Gábor Nyúl
A1 - Franz Lindbichler
A1 - Andrea Ruppert
ED - Emanuele Neri
ED - Davide Caramella
ED - Carlo Bartolozzi
AB - Colorectal cancer represents the third most commonly diagnosedcancer and is the second leading cause of cancer deaths in the United States (Gazelle et al. 2000). In addition, colorectal cancer is responsible for about 11% of all new cancer cases per year (Gazelle et al. 2000). Five-year prognosis is about 90% for patients with localized disease compared to 60% if there is a regional spread and a drop to 10% in patients with distant metastasis (Gazelle et al. 2000). In the field of medicine there is a widely accepted opinion that most colorectal cancers arise from pre-existent adenomatous polyps (Johnson 2000). Therefore, different societies, such as the American Cancer Society, have proposed screening for colorectal cancer (Byers et al. 1997; Winawer et al. 1997). Today, different options exist for detection of colorectal cancer, including digital rectal examination, fecal occult blood testing, flexible and rigid sigmoidoscopy, barium enema and its variants, colonoscopy and recently computed tomography or magnetic resonance-based virtual colonography (Gazelle et al. 2000).

JF - Image Processing in Radiology
PB - Springer-Verlag
CY - Berlin
N1 - doi: 10.1007/978-3-540-49830-8_18
ER -
TY - ABST
T1 - Virtual Planning Tool for Surgical Planning
Y1 - 2008
A1 - Endre Varga
A1 - Balázs Erdőhelyi
N1 - Besorolás ismeretlen
Besorolás ismeretlen
ER -
TY - JOUR
T1 - 3D segmentation of liver, kidneys and spleen from CT images
JF - INTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY
Y1 - 2007
A1 - György Bekes
A1 - László Gábor Nyúl
A1 - Eörs Máté
A1 - Attila Kuba
A1 - Márta Fidrich
AB - The clinicians often need to segment the abdominal organs forradiotherapy planning. Manual segmentation of these organs is very time-consuming, therefore automated methods are desired. We developed a semi-automatic segmentation method to outline liver, spleen and kidneys. It works on CT images without contrast intake that are acquired with a routine clinical protocol. From an initial surface around a user defined seed point, the segmentation of the organ is obtained by an active surface algorithm. Pre- and post-processing steps are used to adapt the general method for specific organs. The evaluation results show that the accuracy of our method is about 90%, which can be further improved with little manual editing, and that the precision is slightly higher than that of manual contouring. Our method is accurate, precise and fast enough to use in the clinical practice.

VL - 2
SN - 1861-6410
IS - 1 SUPPL.
N1 - ScopusID: 34250685687doi: 10.1007/s11548-007-0083-7
JO - INT J COMPUT ASSIST RADIOL SURG
ER -
TY - CHAP
T1 - A 3-subiteration surface-thinning algorithm
T2 - Computer Analysis of Images and Patterns
Y1 - 2007
A1 - Kálmán Palágyi
ED - Walter G Kropatsch
ED - Martin Kampel
ED - Allan Hanbury
AB - Thinning is an iterative layer by layer erosion for extractingskeleton. This paper presents an efficient parallel 3D thinning algorithm which produces medial surfaces. A three-subiteration strategy is proposed: the thinning operation is changed from iteration to iteration with a period of three according to the three deletion directions. © Springer-Verlag Berlin Heidelberg 2007.

JF - Computer Analysis of Images and Patterns
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Vienna, Austria
SN - 978-3-540-74271-5
JO - LNCS
ER -
TY - BOOK
T1 - Advances in Discrete Tomography and Its Applications
T2 - Advances in Discrete Tomography and Its Applications
Y1 - 2007
A1 - Gábor T. Herman
A1 - Attila Kuba
AB - Advances in Discrete Tomography and Its Applications is a unified presentation of new methods, algorithms, and select applications that are the foundations of multidimensional image reconstruction by discrete tomographic methods. The self-contained chapters, written by leading mathematicians, engineers, and computer scientists, present cutting-edge research and results in the field. Three main areas are covered: foundations, algorithms, and practical applications. Following an introduction that reports the recent literature of the field, the book explores various mathematical and computational problems of discrete tomography including new applications. Topics and Features: * introduction to discrete point X-rays * uniqueness and additivity in discrete tomography * network flow algorithms for discrete tomography * convex programming and variational methods * applications to electron microscopy, materials science, nondestructive testing, and diagnostic medicine Professionals, researchers, practitioners, and students in mathematics, computer imaging, biomedical imaging, computer science, and image processing will find the book to be a useful guide and reference to state-of-the-art research, methods, and applications. ` `

JF - Advances in Discrete Tomography and Its Applications
PB - Birkhauser
ER -
TY - CHAP
T1 - Appearance-based Approach to Extract an Age-related Biomarker from Retinal Images
T2 - 3rd Russian-Bavarian Conference on Bio-Medical Engineering, Proceedings
Y1 - 2007
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - László Gábor Nyúl
A1 - Simone Wärntges
A1 - Georg Michelson
A1 - Joachim Hornegger
ED - Joachim Hornegger
ED - Ernst W Mayr
ED - Sergey Schookin
ED - Hubertus Feußner
ED - Nassir Navab
ED - Yuri V. Gulyaev
ED - Kurt Höller
ED - Victor Ganzha
AB - We present an appearance-based method that extracts a new age-related biomarker from retina images. The Principal Component Analysis is applied on intensity values of the illumination corrected green channel of fundus images. The algorithm does not use segmentation, is robust and shows a high range of reliability. It identiﬁed an age-related feature with a strong inﬂuence of the temporal parapapillary area and the optic nerve head. The feature correlates with chronological age of the participants and is signiﬁcantly inﬂuenced by the appearance of cardiovascular risk factors such as smoking and hypertension, and thus it can be designated a biomarker. We extract and validate a medical parameter from retina images applying a purely data-driven approach without using any prior knowledge.

JF - 3rd Russian-Bavarian Conference on Bio-Medical Engineering, Proceedings
PB - Friedrich-Alexander University Erlangen-Nuremberg
CY - Erlangen
VL - 1
ER -
TY - THES
T1 - Binary Tomography Using Geometrical Priors: Uniqueness and Reconstruction Results
Y1 - 2007
A1 - Péter Balázs
PB - University of Szeged
CY - Szeged, Hungary
ER -
TY - CHAP
T1 - Classifying Glaucoma with Image-based Features from Fundus Photographs
T2 - Pattern Recognition
Y1 - 2007
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - Georg Michelson
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
ED - Fred A Hamprecht
ED - Christoph Schnorr
ED - Bernd Jähne
AB - Glaucoma is one of the most common causes of blindness and it isbecoming even more important considering the ageing society. Because healing of died retinal nerve fibers is not possible early detection and prevention is essential. Robust, automated mass-screening will help to extend the symptom-free life of affected patients. We devised a novel, automated, appearance based glaucoma classification system that does not depend on segmentation based measurements. Our purely data-driven approach is applicable in large-scale screening examinations. It applies a standard pattern recognition pipeline with a 2-stage classification step. Several types of image-based features were analyzed and are combined to capture glaucomatous structures. Certain disease independent variations such as illumination inhomogeneities, size differences, and vessel structures are eliminated in the preprocessing phase. The “vessel-free” images and intermediate results of the methods are novel representations of the data for the physicians that may provide new insight into and help to better understand glaucoma. Our system achieves 86 % success rate on a data set containing a mixture of 200 real images of healthy and glaucomatous eyes. The performance of the system is comparable to human medical experts in detecting glaucomatous retina fundus images.

JF - Pattern Recognition
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Heidelberg
SN - 978-3-540-74933-2
N1 - ScopusID: 38149039478doi: 10.1007/978-3-540-74936-3_36
JO - LNCS
ER -
TY - JOUR
T1 - Contour line thinning and multigrid generation of raster-based digital elevation models
JF - INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SCIENCE
Y1 - 2007
A1 - Endre Katona
AB - Thin plate spline interpolation is a widely used approach to generate a digital elevation model (DEM) from contour lines and scattered data. In practice, contour maps are scanned and vectorized, and after resampling in the target grid resolution, interpolation is performed. In this paper we demonstrate the limited accuracy of this process, and propose a high‐resolution processing method (without vectorization) that ensures maximum utilization of information in the source data. First, we discuss the mathematical background of thin plate spline interpolation, and explain the multigrid relaxation principle used to speed up convergence. After, we will show why fine tuning is necessary, especially when contour lines and elevation points are processed at the same time. Finally, our own contour thinning method that produces a significant reduction of elevation bias is described.

PB - Taylor & Francis
VL - 21
SN - 1365-8816
IS - 1-2
N1 - UT: 000244002100004doi: 10.1080/13658810600816474
JO - INT J GEOGR INF SCI
ER -
TY - CHAP
T1 - Decomposition Algorithms for Reconstructing Discrete Sets with Disjoint Components
T2 - ADVANCES IN DISCRETE TOMOGRAPHY AND ITS APPLICATIONS
Y1 - 2007
A1 - Péter Balázs
ED - Gábor T Herman
ED - Attila Kuba
AB - The reconstruction of discrete sets from their projections is a frequently studied field in discrete tomography with applications in electron microscopy, image processing, radiology, and so on. Several efficient reconstruction algorithms have been developed for certain classes of discrete sets having some good geometrical properties. On the other hand, it has been shown that the reconstruction under certain circumstances can be very time-consuming, even NP-hard. In this chapter we show how prior information that the set to be reconstructed consists of several components can be exploited in order to facilitate the reconstruction. We present some general techniques to decompose a discrete set into components knowing only its projections and thus reduce the reconstruction of a general discrete set to the reconstruction of single components, which is usually a simpler task.

JF - ADVANCES IN DISCRETE TOMOGRAPHY AND ITS APPLICATIONS
T3 - Applied and Numerical Harmonic Analysis
PB - Birkhauser Boston
CY - Cambridge
SN - 978-0-8176-3614-2
N1 - UT: 000271523600010doi: 10.1007/978-0-8176-4543-4_8
ER -
TY - JOUR
T1 - A decomposition technique for reconstructing discrete sets from four projections
JF - IMAGE AND VISION COMPUTING
Y1 - 2007
A1 - Péter Balázs
AB - The reconstruction of discrete sets from four projections is in general an NP-hard problem. In this paper we study the class of decomposable discrete sets and give an efficient reconstruction algorithm for this class using four projections. It is also shown that an arbitrary discrete set which is Q-convex along the horizontal and vertical directions and consists of several components is decomposable. As a consequence of decomposability we get that in a subclass of *hv*-convex discrete sets the reconstruction from four projections can also be solved in polynomial time. Possible extensions of our method are also discussed.

PB - Elsevier
VL - 25
SN - 0262-8856
IS - 10
N1 - UT: 000249047200009ScopusID: 34447547739doi: 10.1016/j.imavis.2006.06.015
JO - IMAGE VISION COMPUT
ER -
TY - CHAP
T1 - Discrete Tomography Methods for Nondestructive Testing.
T2 - Advances in Discrete Tomography and Its Applications
Y1 - 2007
A1 - Joachim Baumann
A1 - Zoltán Kiss
A1 - Sven Krimmel
A1 - Attila Kuba
A1 - Antal Nagy
A1 - Lajos Rodek
A1 - Burkhard Schillinger
A1 - Juergen Stephan
ED - Gábor T Herman
ED - Attila Kuba
AB - The industrial nondestructive testing (NDT) of objects seems to be an ideal application of discrete tomography. In many cases, the objects consist of known materials, and a lot of a priori information is available (e.g., the description of an ideal object, which is similar to the actual one under investigation). One of the frequently used methods in NDT is to take projection images of the objects by some transmitting ray (e.g., X- or neutron-ray) and reconstruct the cross sections. But it can happen that only a few number of projections can be collected, because of long and/or expensive data acquisition, or the projections can be collected only from a limited range of directions. The chapter describes two DT reconstruction methods used in NDT experiments, shows the results of a DT procedure applied in the reconstruction of oblong objects having projections only from a limited range of angles, and, finally, suggests a few further possible NDT applications of DT.

JF - Advances in Discrete Tomography and Its Applications
T3 - Applied and Numerical Harmonic Analysis
PB - Birkhauser
SN - 978-0-8176-3614-2
N1 - doi: 10.1007/978-0-8176-4543-4_14
ER -
TY - CHAP
T1 - Effects of Preprocessing Eye Fundus Images on Appearance Based Glaucoma Classification
T2 - Computer Analysis of Images and Patterns
Y1 - 2007
A1 - Jörg Meier
A1 - Rudriger Bock
A1 - Georg Michelson
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
ED - Walter G Kropatsch
ED - Martin Kampel
ED - Allan Hanbury
AB - Early detection of glaucoma is essential for preventing one ofthe most common causes of blindness. Our research is focused on a novel automated classification system based on image features from fundus photographs which does not depend on structure segmentation or prior expert knowledge. Our new data driven approach that needs no manual assistance achieves an accuracy of detecting glaucomatous retina fundus images compareable to human experts. In this paper, we study image preprocessing methods to provide better input for more reliable automated glaucoma detection. We reduce disease independent variations without removing information that discriminates between images of healthy and glaucomatous eyes. In particular, nonuniform illumination is corrected, blood vessels are inpainted and the region of interest is normalized before feature extraction and subsequent classification. The effect of these steps was evaluated using principal component analysis for dimension reduction and support vector machine as classifier.

JF - Computer Analysis of Images and Patterns
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Berlin; Heidelberg
SN - 978-3-540-74271-5
N1 - ScopusID: 38149068236doi: 10.1007/978-3-540-74272-2_21
JO - LNCS
ER -
TY - CONF
T1 - Efficient Implementation of 3D Thinning Algorithms
T2 - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2007
Y1 - 2007
A1 - Kálmán Palágyi
ED - Attila Fazekas
ED - András Hajdú
JF - A Képfeldolgozók és Alakfelismerők Társaságának konferenciája - KÉPAF 2007
PB - Képfeldolgozók és Alakfelismerők Társasága
CY - Debrecen
ER -
TY - CHAP
T1 - Emission discrete tomography.
T2 - ADVANCES IN DISCRETE TOMOGRAPHY AND ITS APPLICATIONS
Y1 - 2007
A1 - Elena Barcucci
A1 - Andrea Frosini
A1 - Attila Kuba
A1 - Antal Nagy
A1 - Simone Rinaldi
A1 - Martin Samal
A1 - Steffen Zopf
ED - Gábor T Herman
ED - Attila Kuba
AB - Three problems of emission discrete tomography (EDT) are presented. The first problem is the reconstruction of measurable plane sets from two absorbed projections. It is shown that Lorentz theorems can be generalized to this case. The second is the reconstruction of binary matrices from their absorbed row and columns sums if the absorption coefficient is μ0 = log((1+v^{/}5)/2). It is proved that the reconstruction in this case can be done in polynomial time. Finally, a possible application of EDT in single photon emission computed tomography (SPECT) is presented: Dynamic structures are reconstructed after factor analysis.

JF - ADVANCES IN DISCRETE TOMOGRAPHY AND ITS APPLICATIONS
T3 - Applied and Numerical Harmonic Analysis
PB - Birkhauser Boston
CY - Cambridge
SN - 978-0-8176-3614-2
N1 - doi: 10.1007/978-0-8176-4543-4_15
ER -
TY - JOUR
T1 - Extraction of an Age-Related Biomarker From Retinal Images Using Appearance Based Approach
JF - INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
Y1 - 2007
A1 - Georg Michelson
A1 - Simone Wärntges
A1 - Rudriger Bock
A1 - László Gábor Nyúl
A1 - Joachim Hornegger
AB - Purpose:To develop an appropriate algorithm from retina imagesusing an appearance-based version of the Principal Component Analysis and to test the age-related biomarker’s significance for patients at cardiovascular risk. Methods:Sixty-five men (age, 44.2 ± 11.4 years) and 60 women (age, 48.8 ± 12.6 years) without cardiovascular risk factors and without pathologic eye diagnosis were acquired during a clinical non-experimental cross-sectional survey and represented the control group. Forty-four hypertensive men (age, 45.5 ± 9.4 years; hypertensive for 5.9 ± 6.7 years) and 26 hypertensive women (age, 51.2 ± 7.3 years; hypertensive for 7.9 ± 7.1 years) as well as 57 male smokers (age, 41.8 ± 8.5 years; smoking for 20.6 ± 9.8 years; 15.3 ± 8.6 cigarettes per day) and 60 female smokers (age, 43.2 ± 9.5 years; smoking for 20.1 ± 10.7 years; 13.5 ± 8.1 cigarettes per day) were matched for age and sex to the respective number of control subjects. Results:The reliability of the algorithm was 0.958. The retinal biomarker correlated with age (men, -0.284, p = 0.017; women, -0.374, p = 0.001). Smokers showed a lower biomarker value (male, -0.16 ± 1.29; female, -0.12 ± 0.11) than age-matched control subjects (male, 0.72 ± 0.92, p < 0.001; female, 0.24 ± 0.98, p = 0.048). Hypertension had a similar influence to the biomarker in men (0.10 ± 0.84), but not in women (-0.46 ± 1.23) as compared to age-matched controls (male, 0.57 ± 0.95, p = 0.01; female, 0.06 ± 0.99, p = 0.09). Conclusions:The algorithm of the appearance-based version of the Principal Component Analysis identified an age-related image feature dependent on light intensity with a strong influence to the temporal parapapillary area. It may be used to identify patients at cardiovascular risk.

VL - 48
SN - 0146-0404
IS - 5
N1 - ARVO Meeting Abstracts
JO - INVEST OPHTH VIS SCI
ER -
TY - CHAP
T1 - Eye Fundus Image Processing System for Automated Glaucoma Classification
T2 - 52nd IWK - Internationales Wissenschaftliches Kolloquium - Volume II.
Y1 - 2007
A1 - Jörg Meier
A1 - Rudriger Bock
A1 - László Gábor Nyúl
A1 - Georg Michelson
ED - P Scharff
JF - 52nd IWK - Internationales Wissenschaftliches Kolloquium - Volume II.
PB - Technische Universitat
CY - Ilmenau
UR - http://www.db-thueringen.de/servlets/DerivateServlet/Derivate-12272/IWK_2007_2.pdf
ER -
TY - THES
T1 - The 'Gas of Circles' Model and its Application to Tree Crown Extraction
Y1 - 2007
A1 - Peter Horvath
PB - University of Nice - Sophia Antipolis and University of Szeged
VL - PhD
ER -
TY - CONF
T1 - A 'gas of Circles' Phase Field Model and its Application to Tree Crown Extraction
T2 - Proceedings of the European Signal Processing Conference (EUSIPCO)
Y1 - 2007
A1 - Peter Horvath
A1 - Ian Jermyn
ED - Marek Domanski
ED - Ryszard Stasinski
ED - Maciej Bartkowiak
JF - Proceedings of the European Signal Processing Conference (EUSIPCO)
CY - Poznan, Poland
ER -
TY - CHAP
T1 - Generation and empirical investigation of hv-Convex discrete sets
T2 - Image Analysis
Y1 - 2007
A1 - Péter Balázs
ED - Bjarne Kjær Ersbøll
ED - Kim Steenstrup Pedersen
AB - One of the basic problems in discrete tomography is thereconstruction of discrete sets from few projections. Assuming that the set to be reconstructed fulfils some geometrical properties is a commonly used technique to reduce the number of possibly many different solutions of the same reconstruction problem. Since the reconstruction from two projections in the class of so-called hv-convex sets is NP-hard this class is suitable to test the efficiency of newly developed reconstruction algorithms. However, until now no method was known to generate sets of this class from uniform random distribution and thus only ad hoc comparison of several reconstruction techniques was possible. In this paper we first describe a method to generate some special hv-convex discrete sets from uniform random distribution. Moreover, we show that the developed generation technique can easily be adapted to other classes of discrete sets, even for the whole class of hv- convexes. Several statistics are also presented which are of great importance in the analysis of algorithms for reconstructing hv-convex sets. © Springer-Verlag Berlin Heidelberg 2007.

JF - Image Analysis
T3 - Lecture Notes in Computer Science
PB - Springer Verlag
CY - Aalborg, Denmark
SN - 978-3-540-73039-2
N1 - UT: 000247364000035ScopusID: 38049002073
JO - LNCS
ER -
TY - THES
T1 - Markovian Image Models and their Application in Image Segmentation
Y1 - 2007
A1 - Zoltan Kato
ER -
TY - PAT
T1 - Method and system for automatically transforming CT studies to a common reference frame
Y1 - 2007
A1 - Attila Tanacs
A1 - Eörs Máté
A1 - Attila Kuba
ER -
TY - CONF
T1 - A Multispectral Data Model for Higher-Order Active Contours and its Application to Tree Crown Extraction
T2 - Proceedings of the Advanced Concepts for Intelligent Vision Systems (ACIVS)
Y1 - 2007
A1 - Peter Horvath
ED - Wilfried Philips
ED - Dan Popescu
ED - Paul Scheunders
JF - Proceedings of the Advanced Concepts for Intelligent Vision Systems (ACIVS)
CY - Delft, Netherlands
VL - 4678
ER -
TY - CONF
T1 - A New Phase Field Model of a 'gas of Circles' for Tree Crown Extraction from Aerial Images
T2 - Proceedings of the International Conference on Computer Analysis of Images and Patterns (CAIP)
Y1 - 2007
A1 - Peter Horvath
A1 - Ian Jermyn
ED - Walter G. Kropatsch
ED - Martin Kampel
ED - Allan Hanbury
JF - Proceedings of the International Conference on Computer Analysis of Images and Patterns (CAIP)
CY - Vienna, Austria
VL - 4673
ER -
TY - CHAP
T1 - Reconstructing some hv-convex binary images from three or four projections
T2 - Proccedings of the 5th International Symposium on Image and Signal Processing and Analysis
Y1 - 2007
A1 - Péter Balázs
ED - M Petrou
ED - T Saramaki
ED - Aytul Ercil
ED - Sven Lončarić
AB - The reconstruction of binary images from their projections is animportant problem in discrete tomography. The main challenge in this task is that in certain cases the projections do not uniquely determine the binary image. This can yield an extremely large number of (sometimes very different) solutions. Moreover, under certain circumstances the reconstruction becomes NP-hard. A commonly used technique to reduce ambiguity and to avoid intractability is to suppose that the image to be reconstructed arises from a certain class of images having some geometrical properties. This paper studies the reconstruction problem in the class of hv-convex images having their components in so-called decomposable configurations. First, we give a negative result showing that there can be exponentially many images of the above class having the same three projections. Then, we present a heuristic that uses four projections to reconstruct an hv-convex image with decomposable configuration. We also analyze the performance of our heuristic from the viewpoints of accuracy and running time.

JF - Proccedings of the 5th International Symposium on Image and Signal Processing and Analysis
PB - IEEE
CY - Istanbul, Turkey
SN - 978-953-184-116-0
N1 - UT: 000253387900025ScopusID: 7949129892doi: 10.1109/ISPA.2007.4383678
ER -
TY - CONF
T1 - Retina Image Analysis System for Glaucoma Detection
T2 - BMT 2007: 41. Jahrestagung der Deutschen Gesellschaft für Biomedizinische Technik im VDE
Y1 - 2007
A1 - Rudriger Bock
A1 - Jörg Meier
A1 - László Gábor Nyúl
A1 - Georg Michelson
A1 - Joachim Hornegger
JF - BMT 2007: 41. Jahrestagung der Deutschen Gesellschaft für Biomedizinische Technik im VDE
CY - Aachen, Germany
N1 - Art. No.: 1569047505
ER -
TY - CHAP
T1 - A subiteration-based surface-thinning algorithm with a period of three
T2 - Pattern Recognition
Y1 - 2007
A1 - Kálmán Palágyi
ED - Fred A Hamprecht
ED - Christoph Schnorr
ED - Bernd Jähne
AB - Thinning on binary images is an iterative layer by layer erosionuntil only the "skeletons" of the objects are left. This paper presents an efficient parallel 3D surface-thinning algorithm. A three-subiteration strategy is proposed: the thinning operation is changed from iteration to iteration with a period of three according to the three deletion directions. © Springer-Verlag Berlin Heidelberg 2007.

JF - Pattern Recognition
T3 - Lecture Notes on Computer Science
PB - Springer Verlag
CY - Heidelberg, Germany
SN - 978-3-540-74933-2
N1 - ScopusID: 38149004908
JO - LNCS
ER -
TY - CONF
T1 - Surgical Planning Tool with Biomechanical Simulation
T2 - International Conference on Computer Assisted Radiology and Surgery (CARS)
Y1 - 2007
A1 - Balázs Erdőhelyi
A1 - Endre Varga
A1 - Attila Kuba
AB - The fixation of fractured bones often needs a very careful decision making. The operation has to be designed very carefully. A computer assisted system can help the surgeon in the planning phase to increase surgical accuracy. This paper introduces a software tool to plan a surgical intervention and to calculate the biomechanical stability of the plan. The proposed system provides 3D movement and rotation of the bone fragments and the insertion of fixation screws and plates. Finite element analysis is used to calculate mechanical stability of the surgical plan. Using these results the surgeon is able to see the week points of the fixation before the surgery. He can even try several surgical plans to pick the most promising one. ` `

JF - International Conference on Computer Assisted Radiology and Surgery (CARS)
PB - Springer
CY - Berlin, Germany
VL - 2
ER -
TY - ABST
T1 - A Three-layer MRF model for Object Motion Detection in Airborne Images
Y1 - 2007
A1 - Csaba Benedek
A1 - Tamas Sziranyi
A1 - Zoltan Kato
A1 - Josiane Zerubia
ER -
TY - CHAP
T1 - Whole Body MRI Intensity Standardization
T2 - Bildverarbeitung für die Medizin 2007
Y1 - 2007
A1 - Florian Jäger
A1 - László Gábor Nyúl
A1 - Bernd Frericks
A1 - Frank Wacker
A1 - Joachim Hornegger
ED - Alexander Horsch
ED - Thomas Martin Deserno
ED - Heinz Handels
ED - Hans-Peter Meinzer
ED - Thomas Tolxdorff
AB - A major problem of segmentation of magnetic resonance images isthat intensities are not standardized like in computed tomography. This article deals with the correction of inter volume intensity differences that lead to a missing anatomical meaning of the observed gray values. We present a method for MRI intensity standardization of whole body MRI scans. The approach is based on the alignment of a learned reference and the current histogram. Each of these histograms is at least 2-d and represents two or more MRI sequences (e.g., T1- and T2-weighted images). From the matching a non-linear correction function is gained which describes a mapping between the intensity spaces and consequently adapts the image statistics to a known standard. As the proposed intensity standardization is based on the statistics of the data sets only, it is independent from spatial coherences or prior segmentations of the reference and newly acquired images. Furthermore, it is not designed for a particular application, body region or acquisition protocol. The method was evaluated on whole body MRI scans containing data sets acquired by T1/FL2D and T2/TIRM sequences. In order to demonstrate the applicability, examples from noisy and pathological image series acquired on a whole body MRI scanner are given.

JF - Bildverarbeitung für die Medizin 2007
T3 - Informatik aktuell
PB - Springer-Verlag
CY - München, Germany
SN - 978-3-540-71090-5
N1 - doi: 10.1007/978-3-540-71091-2_92
ER -
TY - CONF
T1 - A Higher-Order Active Contour Model for Tree Detection
T2 - Proceedings of the International Conference on Pattern Recognition (ICPR)
Y1 - 2006
A1 - Peter Horvath
A1 - Ian Jermyn
A1 - Zoltan Kato
A1 - Josiane Zerubia
AB - We present a model of a 'gas of circles', the ensemble of regions in the image domain consisting of an unknown number of circles with approximately fixed radius and short range repulsive interactions, and apply it to the extraction of tree crowns from aerial images. The method uses the recently introduced 'higher order active contours' (HOACs), which incorporate long-range interactions between contour points, and thereby include prior geometric information without using a template shape. This makes them ideal when looking for multiple instances of an entity in an image. We study an existing HOAC model for networks, and show via a stability calculation that circles stable to perturbations are possible for constrained parameter sets. Combining this prior energy with a data term, we show results on aerial imagery that demonstrate the effectiveness of the method and the need for prior geometric knowledge. The model has many other potential applications. ` `

JF - Proceedings of the International Conference on Pattern Recognition (ICPR)
PB - IAPR
CY - Hong Kong, China
VL - 2
ER -
TY - JOUR
T1 - Image reconstruction and correction methods in neutron and X-ray tomography
JF - Acta Cybernetica
Y1 - 2006
A1 - Zoltán Kiss
A1 - Lajos Rodek
A1 - Attila Kuba
AB - Neutron and X-ray tomography are imaging techniques for getting information about the interior of objects in a non-destructive way. They reconstruct cross-sections from projection images of the object being investigated. Due to the properties of the image acquisition system, the projection images are distorted by several artifacts, and these reduce the quality of the reconstruction. In order to eliminate these harmful effects the projection images should be corrected before reconstruction. Taking projections is usually an expensive and time consuming procedure. One of our main goals has been to try to minimize the number of projections - for example, by exploiting more a priori information. A possible way of reducing the number of projections is by the application of discrete tomographic methods. In this case a special class of objects can be reconstructed, consisting of only a few homogenous materials that can be characterized by known discrete absorption values. To this end we have implemented two reconstruction methods. One is able to reconstruct objects consisting of cylinders and spheres made of homogeneous materials only. The other method is a general one in the sense that it can be used for reconstructing any shape. Simulations on phantoms and physical measurements were carried out and the results are presented here. ` `

PB - University of Szeged
CY - Szeged, Hungary
VL - 17
ER -
TY - CONF
T1 - Multi-resolution method for binary tomography
T2 - Workshop on Discrete Tomography and its Applications (WDTA)
Y1 - 2005
A1 - László Ruskó
A1 - Attila Kuba
AB - Multi-resolution and region-growing strategies have been successfully used in several fields of image processing. In this paper we investigate how these two strategies can be applied for binary tomography. We included these strategies into a reconstruction method using simulated annealing and tested these new methods on different images. ` `

JF - Workshop on Discrete Tomography and its Applications (WDTA)
CY - New York City, USA
VL - Proceedings of the Workshop on Discrete Tomography and its Applications (WDTA)
ER -
TY - JOUR
T1 - Preliminary studies of discrete tomography in neutron imaging
JF - IEEE Transactions on Nuclear Science
Y1 - 2005
A1 - Atila Kuba
A1 - László Ruskó
A1 - Lajos Rodek
A1 - Zoltán Kiss
AB - Discrete tomography (DT) is a new technique to reconstruct discrete images from their projections (like neutron images). The reconstruction methods in DT are different from the conventional ones, because the created images may contain only a few numbers of given discrete values. One of the main reasons to apply DT is that hopefully we need only a few numbers of projections. In many applications we have a situation where we know the material components of the object to be studied, that is, we know the discrete values of the image to be reconstructed. Using discreteness and some a priori information we can apply several DT methods in neutron imaging. Most of the DT reconstruction methods are reducing the problem to an optimization task. We tried two such methods on software and physical phantoms. In these experiments we investigated the effects of the following parameters: number of projections, noise levels, and complexity of the object to be reconstructed. We also developed a software system, called DIRECT, for testing different DT methods, to compare them and to present the reconstructed objects. ` `

PB - IEEE
VL - 52
ER -
TY - Generic
T1 - Proceedings of the Workshop on Discrete Tomography and its Applications
T2 - Workshop on Discrete Tomography and its Applications
Y1 - 2005
A1 - Gábor T. Herman
A1 - Attila Kuba
JF - Workshop on Discrete Tomography and its Applications
PB - Elsevier
VL - Electronic Notes in Discrete Mathematics
ER -
TY - JOUR
T1 - A sufficient condition for non-uniqueness in binary tomography with absorption
JF - Theoretical Computer Science
Y1 - 2005
A1 - Attila Kuba
A1 - Maurice Nivat
AB - A new kind of discrete tomography problem is introduced: the reconstruction of discrete sets from their absorbed projections. A special case of this problem is discussed, namely, the uniqueness of the binary matrices with respect to their absorbed row and column sums when the absorption coefficient is n=log((1+5^0.5)/2). It is proved that if a binary matrix contains a special structure of 0s and 1s, called alternatively corner-connected component, then this binary matrix is non-unique with respect to its absorbed row and column sums. Since it has been proved in another paper [A. Kuba, M. Nivat, Reconstruction of discrete sets with absorption, Linear Algebra Appl. 339 (2001) 171194] that this condition is also necessary, the existence of alternatively corner-connected component in a binary matrix gives a characterization of the non-uniqueness in this case of absorbed projections. ` `

VL - 346
ER -
TY - JOUR
T1 - Image registration methods based on interactively identified point pairs
JF - Alkamazott Matematikai Lapok
Y1 - 2004
A1 - Attila Tanacs
VL - 21
ER -
TY - JOUR
T1 - 3D-Querschnittsprofil des Laryngotrachealtrakts—Eine neue Methode zur Visualisierung und Quantifizierung von Trachealstenosen
JF - Der Radiologe
Y1 - 2003
A1 - Sorantin, Erich.
A1 - Halmai, Csongor.
A1 - Balázs Erdőhelyi
A1 - Kálmán Palágyi
A1 - László Gábor Nyúl
A1 - Ollé, Krisztián.
A1 - Geiger, B.
A1 - Lindbichler, F.
A1 - Friedrich, G.
A1 - Kiesler, K.
AB - ### Purpose

Demonstration of a technique for 3D assessment of tracheal stenoses, regarding site, length and degree, based on spiral computed tomography (S-CT).

### Patients and Methods

S-CT scanning and automated segmentation of the laryngo-tracheal tract (LTT) was followed by the extraction of the LTT medial axis using a skeletonisation algorithm. Orthogonal to the medial axis the LTT 3D cross sectional profile was computed and presented as line charts, where degree and length were obtained. Values for both parameters were compared between 36 patients and 18 normal controls separately. Accuracy and precision was derived from 17 phantom studies.

### Results

Average degree and length of tracheal stenoses were found to be 60.5% and 4.32 cm in patients compared to minor caliber changes of 8.8% and 2.31 cm in normal controls (p <0.005). For the phantoms an excellent correlation between the true and computed 3D cross sectional profile was found (p <0.005) and an accuray for length and degree measurements of 2.14 mm and 2.53% respectively could be determined. The corresponding figures for the precision were found to be 0.92 mm and 2.56%.

### Conclusion

LTT 3D cross sectional profiles permit objective, accurate and precise assessment of LTT caliber changes. Minor LTT caliber changes can be observed even in normals and, in case of an otherwise normal S-CT study, can be regarded as artefacts.

PB - Springer-Verlag
VL - 43
UR - http://dx.doi.org/10.1007/s00117-003-0990-8
ER -
TY - JOUR
T1 - Discrete tomography in medical imaging
JF - Proceedings of the IEEE
Y1 - 2003
A1 - Gábor T. Herman
A1 - Attila Kuba
VL - 91
ER -
TY - CONF
T1 - Composition of Radiography Pictures of Whole Helicopter Rotor Blades in Hungary
T2 - 7th World Conference on Neutron Radiography (WCNR)
Y1 - 2002
A1 - Márton Balaskó
A1 - Zoltán Balaskó
A1 - Emese Balogh
A1 - Attila Tanacs
A1 - Endre Katona
A1 - Attila Kuba
JF - 7th World Conference on Neutron Radiography (WCNR)
ER -
TY - JOUR
T1 - Mathematical generation of normal data for evaluating myocardial perfusion studies
JF - IEEE Transactions on Medical Imaging
Y1 - 2002
A1 - Marianna Dudásné-Nagy
A1 - Eörs Máté
A1 - Béla Kári
VL - 21
ER -
TY - JOUR
T1 - Reconstruction of convex 2D discrete sets in polynomial time
JF - Theoretical Computer Science
Y1 - 2002
A1 - Attila Kuba
A1 - Emese Balogh
AB - The reconstruction problem is considered in those classes of discrete sets where the reconstruction can be performed from two projections in polynomial time. The reconstruction algorithms and complexity results are summarized in the case of hv-convex sets, hv-convex 8-connected sets, hv-convex polyominoes, and directed h-convex sets. As new results some properties of the feet and spines of the hv-convex 8-connected sets are proven and it is shown that the spine of such a set can be determined from the projections in linear time. Two algorithms are given to reconstruct hv-convex 8-connected sets. Finally, it is shown that the directed h-convex sets are uniquely reconstructible with respect to their row and column sum vectors. ` `

VL - 283
ER -
TY - JOUR
T1 - A 3D parallel shrinking algorithm
JF - Acta Cybernetica
Y1 - 2001
A1 - Kálmán Palágyi
AB - Shrinking is a frequently used preprocessing step in image processing. This paper presents an efficient 3D parallel shrinking algorithm for transforming a binary object into its topological kernel. The applied strategy is called directional: each iteration step is composed of six subiterations each of which can be executed in parallel. The algorithm makes easy implementation possible, since deletable points are given by 3x3x3 matching templates. The topological correctness of the algorithm is proved for (26,6) binary pictures. ` `

PB - University of Szeged
CY - Szeged
VL - 15
ER -
TY - JOUR
T1 - Comparison of algorithms for reconstructing hv-convex discrete sets
JF - Linear Algebra and its Applications
Y1 - 2001
A1 - Emese Balogh
A1 - Attila Kuba
A1 - Csaba Devenyi
A1 - Alberto Del Lungo
VL - 339
ER -
TY - JOUR
T1 - Reconstruction of 4- and 8-connected convex discrete sets from row and column projections
JF - Linear Algebra and its Applications
Y1 - 2001
A1 - Sara Brunetti
A1 - Alberto DelLungo
A1 - F. DelRistoro
A1 - Attila Kuba
A1 - Maurice Nivat
AB - In this paper we examine the problem of reconstructing a discrete two-dimensional set from its two orthogonal projection (H,V) when the set satisfies some convexity conditions. We show that the algorithm of the paper [Int. J. Imaging Systems and Technol. 9 (1998) 69] is a good heuristic algorithm but it does not solve the problem for all (H,V) instances. We propose a modification of this algorithm solving the problem for all (H,V) instances, by starting to build the ``spine''. The complexity of our reconstruction algorithm is O(mnˇlog(mn)ˇmin{m2,n2}) in the worst case. However, according to our experimental results, in 99% of the studied cases the algorithm is able to reconstruct a solution without using the newly introduced operation. In such cases the upper bound of the complexity of the algorithm is O(mnˇlog(mn)). A systematic comparison of this algorithm was done and the results show that this algorithm has the better average complexity than other published algorithms. The way of comparison and the results are given in a separate paper [Linear Algebra Appl. (submitted)]. Finally we prove that the problem can be solved in polynomial time also in a class of discrete sets which is larger than the class of convex polyominoes, namely, in the class of 8-connected convex sets. ` `

VL - 339
ER -
TY - JOUR
T1 - Reconstruction of discrete sets with absorption
JF - Linear Algebra and its Applications
Y1 - 2001
A1 - Attila Kuba
A1 - Maurice Nivat
AB - The uniqueness problem is considered when binary matrices are to be reconstructed from their absorbed row and column sums. Let the absorption coefficient n be selected such that en = (1+5^0.5)/2. Then it is proved that if a binary matrix is non-uniquely determined, then it contains a special pattern of 0s and 1s called composition of alternatively corner-connected components. In a previous paper [Discrete Appl. Math. (submitted)] we proved that this condition is also sufficient, i.e., the existence of such a pattern in the binary matrix is necessary and sufficient for its non-uniqueness. ` `

VL - 339
UR - http://www.sciencedirect.com/science/article/B6V0R-44CHW26-C/2/e4cd2b3dc91dbb828db15e331a6230cc
ER -
TY - RPRT
T1 - Bayesian Color Image Segmentation Using Reversible Jump Markov Chain Monte Carlo
Y1 - 1999
A1 - Zoltan Kato
PB - ERCIM/CWI
CY - Amsterdam, The Netherlands
ER -
TY - BOOK
T1 - Discrete Tomography: Foundations, Algorithms, and Applications
T2 - Applied and Numerical Harmonic Analysis
Y1 - 1999
A1 - Gábor T. Herman
A1 - Attila Kuba
JF - Applied and Numerical Harmonic Analysis
PB - Birkhauser
ER -
TY - CONF
T1 - An Interpretation System for Cadastral Maps
T2 - International Conference on Image Analysis and Processing (ICIAP'99)
Y1 - 1999
A1 - Endre Katona
A1 - György Hudra
JF - International Conference on Image Analysis and Processing (ICIAP'99)
PB - IEEE
ER -
TY - Generic
T1 - Assessment of myocardial function with gated SPECT before and after coronary by-pass surgery
Y1 - 1993
A1 - János Mester
A1 - István Kósa
A1 - Eörs Máté
A1 - Vera Matievics
A1 - G Lupkovics
A1 - Gábor Kovács
A1 - László Csernay
JF - European Journal of Nuclear Medicine
VL - 10
ER -
TY - Generic
T1 - Efficiency of the orthopan tomoscintigram (OPTS) in abnormalities of the jaws
Y1 - 1993
A1 - Mária Rajtár
A1 - Eörs Máté
A1 - András Fazekas
A1 - György Szabó
A1 - László Csernay
JF - European Journal of Nuclear Medicine
VL - 10
ER -
TY - Generic
T1 - Investigation of left ventricular wall motion by gated blood-pool SPECT, using three-dimensional display of Fourier phase and amplitude
Y1 - 1993
A1 - János Mester
A1 - István Kósa
A1 - Vera Matievics
A1 - Eörs Máté
A1 - László Csernay
JF - First International Congress of Nuclear Cardiology, Abstract book
ER -
TY - JOUR
T1 - Can Dynamic Krypton-81m Imaging Separate Regional Ventillation and Volume?
JF - Journal of Nuclear Medicine
Y1 - 1992
A1 - MF Lythgoe
A1 - H Deavies
A1 - Attila Kuba
A1 - Mihály Tóth-Abonyi
VL - 33
ER -
TY - JOUR
T1 - Data processing system for nuclear medicine images
JF - International Journal of Imaging Systems and Technology
Y1 - 1992
A1 - Attila Kuba
A1 - Árpád Makay
A1 - Eörs Máté
A1 - László Csernay
VL - 4
ER -
TY - JOUR
T1 - Data processing system for nuclear medicine images
JF - International Journal of Imaging Systems and Technology
Y1 - 1992
A1 - Attila Kuba
A1 - Árpád Makay
A1 - Eörs Máté
A1 - László Csernay
VL - 4
ER -
TY - Generic
T1 - Documentation of changes in regional myocardial function due to coronary bypass surgery by gated SPECT, using three-dimensional display of Fourier phase and amplitude
Y1 - 1992
A1 - János Mester
A1 - Isván Kósa
A1 - Eörs Máté
A1 - G Lupkovics
A1 - Gábor Kovács
A1 - László Csernay
JF - European Heart Journal
VL - 13
ER -
TY - JOUR
T1 - Three-dimensional presentation of the Fourier amplitude and phase: A fast display method for gated cardiac blood-pool SPECT
JF - Journal on Nuclear Medicine
Y1 - 1992
A1 - Eörs Máté
A1 - János Mester
A1 - László Csernay
A1 - Attila Kuba
A1 - S Madani
A1 - Árpád Makay
VL - 33
ER -
TY - Generic
T1 - 3D presentation of the Fourier amplitude and phase. A new fast display method for gated cardiac blood pool SPECT
Y1 - 1991
A1 - János Mester
A1 - Eörs Máté
A1 - László Csernay
A1 - Attila Kuba
A1 - S Madani
A1 - Árpád Makay
JF - European Jounal of Nuclear Medicine
VL - 18
ER -
TY - JOUR
T1 - Detection and localisation of ventricular preexcitation in Wolff-Parkinson-White syndrome (comparative study with body surface mapping)
JF - Nuclear Medicine Communications
Y1 - 1986
A1 - János Mester
A1 - I Preda
A1 - G Kozmann
A1 - Eörs Máté
A1 - L Regos
A1 - K Tóth
A1 - György Marosi
A1 - Zoltán Antalóczy
A1 - László Csernay
VL - 7
ER -
TY - JOUR
T1 - The probabilistic behaviour of the NFD bin packing algorithm
JF - Acta Cybernetica
Y1 - 1986
A1 - János Csirik
A1 - Eörs Máté
VL - 7
ER -