Forthcoming Papers

1995 Artificial Intelligence  
ELSEVIER Forthcoming Papers Special Volume on Vision (N. Ahuja and R. Horaud, Guest Editors) R. Basri and E. Rivlin, Localization and homing using combinations of model views Navigation involves recognizing the environment, identifying the current position within the environment, and reaching particular positions. We present a method for kxxlization (the act of recognizing the environment), positioning (the act of computing the exact coordinates of a robot in the environment), and homing (the
more » ... t of returning to a previously visited position) from visual input. The method is based on representing the scene as a set of 2D views and predicting the appearances of novel views by linear combinations of the model views. The method accurately approximates the appearance of scenes under weak-perspective projection. Analysis of this projection as well as experimental results demonstrate that in many cases this approximation is sufficient to accurately describe the scene. When weak-perspective approximation is invalid, either a larger number of models can be acquired or an iterative solution to account for the perspective distortions can be employed. The method has several advantages over other approaches. It uses relatively rich representations; the representations are 2D rather than 3D; and localization can be done from only a single 2D view without calibration. The same principal method is applied for both the localization and positioning problems, and a simple "qualitative" algorithm for homing is derived from this method. Z. Zhang, R. De&he, 0. Faugeras and Q.-T. Luong, A robust technique for matching two uncalibrated images through the recovery of the unknown epipolar geometry This paper proposes a robust approach to image matching by exploiting the only available geometric constraint, namely, the epipolar constraint. The images are uncalibrated, namely the motion between them and the camera parameters are not known. Thus, the images can be taken by different cameras or a single camera at different time instants. If we make an exhaustive search for the epipolar geometry, the complexity is prohibitively high. The idea underlying our approach is to use classical techniques (correlation and relaxation methods in our particular implementation) to find an initial set of matches, and then use a robust technique-the Least Median of Squares (LMedS)-to discard false matches in this set. The epipolar geometry can then be accurately estimated using a meaningful image criterion. More matches are eventually found, as in stereo matching, by using the recovered epipolar geometry. A large number of experiments have been carried out, and very good results have been obtained. Regarding the relaxation technique, we define a new measure of matching support, which allows a higher tolerance to deformation with respect to rigid transformations in the image plane and a smaller contribution for distant matches than for nearby ones. A new strategy for updating matches is developed, which only Elsevier Science B.V. W.W. Cohen, Pat-learning non-recursive Prolog clauses G. Schwarz, In search of a "true" logic of knowledge: the nonmonotonic perspective M. Stefik and S. Smoliar, The Creative Mind: Myths and Mechanisms: six reviews and a response K.B. Haase, Too many ideas, just one word:
doi:10.1016/0004-3702(95)90021-7 fatcat:dlj6ovgfqjerjmq76jkssdcy3e