Yutaka Ishiyama

Stereo correspondence using segment connectivity

Presents a method to search for stereo correspondence based on the connectivity of segments. The data structure is defined by boundary representation. The free curve can be treated by this data structure not as a straight line approximation, but as a curved line. Some candidates for correspondence pairs consist of two segments in left and right images under epipolar condition. The connectivity of two pairs is decided by their distance, intensity, and angle, based on each boundary in the left image. The similarity of paths, which are sequences of pairs, is evaluated. The main feature of our method is that it can evaluate in general situations because the similarity is calculated based on the connectivity of pairs. Multiple correspondence between pairs is removed using this similarity, and the 3D structure is reconstructed. Applications of our work include recognition for free form objects and tracking in 3D space.

Hyper Frame Vision: a real-time vision system for 6-DOF object localization

A system for robot vision is proposed that integrates a 3-D object recognition task and a 3-D object tracking task, enabling real-time 6-DOF localization of a known continuously moving object. A computational time-lag between the two tasks is absorbed by a large amount of frame memory. For 3-D sensing, calibrated trinocular stereo cameras are used to employ stereo-vision-based object recognition and tracking methods that allow objects of any shape to be dealt with and to provide robust performance in an environment with partial occlusions and cluttered backgrounds. The effectiveness of the system is demonstrated by experimental results.

A tracking based manipulation system built on stereo vision

This paper presents a manipulation system which is based on visual tracking. A tracking function is useful not only for tracking moving objects but also to verify the result of a task and to detect events in various phases of a task. In our system the tracking function is provided by a stereo vision system. Recognition and tracking procedures are based on a geometric model representation that has generality for a wide range of solid objects. The implemented tracking method is robust against partial occlusion of the tracked object and enables short cycle monitoring of the target coordinates. These features make it possible to build a tracking-based manipulation system. A pick-and-insertion task was executed to show various uses of the tracking function.

Labeling board based on boundary tracking

Describes a newly developed labeling board based on an algorithm in a combination of raster scanning and boundary tracking. This board employs the boundary tracking method and does not require a working memory for temporary labels, and thus it can process labels in size 512*512 images without restricting the maximum numbers of connected regions. It can also count holes within regions, and control labeling by using the perimeter of regions, at the same time of labelling. The processing time is 50 msec for size 512*512 real images.<<ETX>>