Accommodation as a Low-Level Visual Cue

Wednesday, October 18, 2000 - 2:00pm - 3:00pm
Keller 3-180
Stefano Soatto (University of California, Los Angeles)
I call accommodation cues measurable properties of images of a given scene that are associated with a change in the geometry of the imaging device. For instance, in the human eye the shape of the lens is controlled so as to bring the scene into focus at the fovea; in a video camera the lens translates for the same purpose.

Is accommodation an unambiguous cue? (i.e. is it possible to distinguish two arbitrary shapes solely from accommodation cues?) Can a surface be reconstructed uniquely from accommodation? Such conditions clearly depend upon geometry (the shape of the surface) as well as photometry (its radiance distribution). Is it possible to characterize the set of sufficiently exciting distributions?

In this talk I will present some preliminary results and partial answers to the above questions, as well as describe two optimal algorithms (in the sense of L2 and Information-divergence) to reconstruct shape from accommodation cues, under certain assumptions. This amounts to solving a blind deconvolution problem with some special features. I will discuss some open problems and potential applications of accommodation in visualization and endoscopic surgery.