Waltz, David L.

Generating Semantic Descriptions from Drawings of Scenes with Shadows


The research reported here concerns the principles used to automatically generate three-dimensional representations from line drawings of scenes. The computer programs involved look at scenes which consist of polyhedra and which may contain shadows and various kinds of coincidentally aligned scene features. Each generated description includes information about edge shape (convex, concave, occluding, shadow, etc.), about the type of illumination for each region (illuminated, projected shadow, or oriented away from the light source), and about the spacial orientation of regions. The methods used are based on the labeling schemes of Huffman and Clowes; this research provides a considerable extension to their work and also gives theoretical explanations to the heuristic scene analysis work of Guzman, Winston, and others. A condensed version appears in Patrick Winston (ed.), The Psychology of Computer Vision, pp. 19{91, New York: McGraw-Hill, 1975.Direct link to PDF.MIT AI Lab Technical Report No AITR-271, November 1