Charlie J. Krey

Segmentation improvement through a robust segment grouping-and-matching algorithm in stereovision

An original algorithm is presented that matches the segments of a pair of stereoscopic images and then improves the edge segmentation of images to make the interpretation process easier. The method does not consider each segment independently to perform the matching, rather it groups and matches the segments simultaneously. First, the linked segments are grouped and matched. Then, the same process is repeated while considering the segments more and more distant. At each step, different criteria such as segment connection type and relative position of the segments are used to select the correct matchings among ail the matching hypotheses. The segmentation improvement takes into account the geometric and topologic properties of objects-the computed sets of segments are considered the projection of the faces of these objects. The segmentation improvement method relies on the comparison of the matched sets obtained previously.

Rule-based system for region segmentation improvement in stereovision

The aim of this work is to develop a method to improve the region segmentation of images by considering each image separately and taking into account the results of the matching process. The method is carried out in several steps. First, an initial region segmentation is computed by using a split-and-merge algorithm cooperating with an edge extractor. Then, a rule-based system is used in order to improve the initial region segmentation. In the second step of the method, the regions of the images are matched by an iterative algorithm; only the reliable matches are performed and for this reason, numerous regions are left unmatched. Then, these regions are treated by another rule-based system by comparing the homologous regions on each image. Both the image segmentation and the matching results are improved at the same time making easier the 3-D reconstruction of the facets corresponding to the matched regions.

Comparison between two axial stereovision systems

In this paper, general characteristics of <1x ia l stcreovision systems arc presented. The advantages and disadvantages of these systems arc examined. The experimental results with video-camera displacement and a video-camera with a 1.00111 system arc present ed and we conclude that it is more interesting to vary video-camera fornl length than to increase he displacement of t he video-camera w it h a fixed focal length.

3D description of indoor scenes based on planar facets reconstruction in stereovision

The aim of this method is to yield a 3D perceptual description fo indoor scenes in order to make easier teh interpretation. The first characteristic is to yield this description with planar facets by using the edge segmentation. First, an iterative and cooperative algorithm creates a 2D perceptual discrimination by matching and grouping the segments simultaneously. Then, this 2D description is used by approximating each set of segments by a 3D planar facet in order to compute the initial 3D description. After some checks at different levels, we look for relations between these facets and an algorithm groups the facets approximating parallel planes. The 3D perceptual description will make easier the interpretation of the scene.

Fuzzy reasoning rule-based system for image segmentation

This paper introduces a general purpose method for black and white image segmentation, which is based on the design of a rule based-system. Rules integrate general knowledge, which is completely independent of environment and scene content ; they process simultanuously regions and lines by merging similar regions, splitting non uniform ones, connecting lines or deleting non significant ones. Rules are selected according to the nature of data under analysis, evaluated by means of a set of performance measurement and ordered according to their efficiency ; only the most efficient ones are really fired. Furthermore, adapted control strategies, using dynamic data selection, allow to focuse the process on the required parts of the image. This paper describes some examples of the rule, and the set of performance measurement for rule efficiency evaluation.