Coplanarity is a relationship of a set of points that exist on a single plane. Coplanarities can be easily observed in a scene with planer surfaces, and these types of coplanarities have been widely used for 3D reconstructions based on geometrical constraints. Other types of coplanarities that can be observed from images are those observed as cross sections of planes and scenes; for example, po...

This paper proposes an efficient technique for human motion recognition based on motion history images and an eigenspace technique. In recent years, human motion recognition has become one of the most popular research fields. It is expected to be applied in a security system, man-machine communication, and so on. In the proposed technique, we use two feature images and the eigenspace technique ...

There is a class of pictures called pictures of impossible objects. Although they are named “impossible,” they are not necessarily impossible. Some of them can be realized as three-dimensional solid objects. In this study, we show that the impression of impossibility comes from the human preference for right angles. This preference can also explain another visual illusion called impossible moti...

One of the serious issues in communication between people is hiding information from the others, and the best way for this, is to deceive them. Since nowadays face images are mostly used in three dimensional format, in this paper we are going to steganography 3-D face images and detecting which by curious people will be impossible. As in detecting face only, its texture is important, we separat...

Contrary to the claim in the literature that the affine reconstruction is possible from two images captured by a translating camera with unknown and varying parameters, we show that such a reconstruction is in fact impossible. In other words, the knowledge that “ the camera’s motion between the two images is just a pure translation” is an insufficient piece of information for affine reconstruct...

Introduction: The main goal of SPECT imaging is to determine activity distribution inside the organs of the body. However, due to photon attenuation, it is almost impossible to do a quantitative study. In this paper, we suggest a mathematical relationship between activity distribution and its corresponding projections using a transfer matrix. Monte Carlo simulation was used to find a precise tr...

Résumé. Un graphe étant un ensemble d’objets liés par une certaine relation typée, le problème de "modularisation" des grands graphes (qui revient à leur partitionnement en classes) peut, alors, être modélisé mathématiquement via l’Analyse Relationnelle. Cette modélisation permet de comparer sur les mêmes bases un certain nombre de critères de découpage de graphe c’est-à-dire de modularisation....