Correctly matching feature points in a pair of images is an important pre-processing step for many computer vision applications. In this talk we propose an efficient method for estimating the number of correct matches without explicitly computing them. In addition, our method estimates the region of overlap between the images. To this end, we propose to analyze the set of matches using the spatial order of the features, as projected to the x-axis of the image. The set of features in each image is thus represented by a sequence. This reduces the analysis of the matching problem to the analysis of the permutation between the sequences.
Using the Kendall distance metric between permutations and natural assumptions on the distribution of the correct and incorrect matches, we show how to estimate the above-mentioned values. We demonstrate the usefulness of our method in two applications: (i) a new halting condition for RANSAC based epipolar geometry estimation methods that considerably reduce the running time, and (ii) discarding spatially unrelated image pairs in the Structure-from-Motion pipeline.
Authors: Lior Talker, Yael Moses, Ilan Shimshoni
Ilan Shimshoni received his B.Sc. in mathematics from the Hebrew University in Jerusalem, his M.Sc. in computer science from the Weizmann Institute of Science, and his Ph.D. in computer science from the University of Illinois at Urbana Champaign (UIUC).
Ilan was a post-doctorate fellow at the faculty of computer science at the Technion, from 1995-1998, and was a member of the faculty of industrial engineering and management from 1998-2005. He joined the department of Information Systems (IS) at Haifa University in October 2005.
His research areas are computer vision, computer graphics and their application to for example archaeology. He is an associate editor of IEEE PAMI.