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 - 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 - 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 - 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 - 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 -