VASC Seminar Announcement ========================= Date: Thursday, 6/1/00 Time: 3:30pm Place: NSH 3002 Speaker: David Jacobs NEC Research Institute http://external.nj.nec.com/homepages/dwj/ Title: Judging Whether Images Come from the Same Object This talk will be about the problem of comparing images, and deciding whether they seem to come from the same object under different viewing conditions, or from different objects. I will discuss two versions of this problem. In the first, the source of variability in the images is due to changes in lighting. I will show that for any two images, it is always possible that they come from the same object under two different, simple lighting conditions. But I'll also show that there is strong probabilistic information available to tell us when two images are unlikely to come from the same object. We have developed an algorithm that uses this information, and applied it to the problem of face recognition under variable illumination. I'll then discuss the problem of comparing silhouettes to judge if they appear to come from the same object with a change in viewing direction. I will focus on the case in which the camera translates, and rotates about a known axis parallel to the image, such as when a mobile robot explores an environment. In this case I'll present an algorithm for determining whether a new silhouette could come from the same object that produced two previously seen silhouettes. This is related to the problem of building models by "space carving", but with unknown camera positions. I'll also discuss some results on the problem of comparing just two silhouettes to decide whether they seem to come from the same object. Joint work with: Ronen Basri Peter Belhumeur Hansen Chen Ian Jermyn