Introduction

Abstract

One of the outstanding problems in image understanding today is the determination of 3D structure from analysis of images. The methods that have been used to address this problem include the analysis of motion, stereo image pairs, texture gradients, photometry, gravity, and symmetry of shapes. The research described herein adds to this list another source of information, shadow geometry, by describing how shadows can be analyzed for the determination of 3D surface orientations (figure 1-1).