Qualitative Depth and Shape from Stereo, in Agreement with Psychophysical Evidence
Abstract
This paper concentrates on the problem of obtaining depth information from binocular disparities. It is motivated by the fact that implementing registration algorithms and using the results for depth computations is hard in practice with real images due to noise and quantization errors. We will show that qualitative depth information can be obtained from stero disparities with almost no computations, and with no prior knowledge(or computation)of camera parameters. The only constraint is that the epipolar plane of the fixation point includes the X-axes of both cameras. We derive two expressions that order all matched points in the images in two distinct depth-consistent fashions from image coordinates only. One is a tilt-related order lambda, which depends only on the polar angles of the matched points, the other is a depth-related order chi. Using lambda for tilt estimation and point separation(in depth)demonstrates some anomalies and unusual characteristics that have been observed in psychophysical experiments, most notably the induced size effect . Furthermore, the same approach can be applied to estimate some qualitative behavior of the normal to the surface of any object in the field of view. More specifically, one can follow changes in the curvature of contour on the surface of an object, with either x- or y-coordinate fixed. Keywords: Stero vision; Qualitative depth; Induced effect; Motion; Pyschophysiology.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA197259
Entities
People
- Daphna Weinshall
Organizations
- Massachusetts Institute of Technology