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 - 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 -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).

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.

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.

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.

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 - 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 - 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 - 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 - 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 -