Accession Number : ADA307079

Title :   The Three-Dimensional Interpretation of a Class of Simple Line-Drawings.

Descriptive Note : Memorandum rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB

Personal Author(s) : Marill, Thomas

PDF Url : ADA307079

Report Date : OCT 1995

Pagination or Media Count : 28

Abstract : We provide a theory of the three dimensional interpretation of a class of line drawings called p-images, which are interpreted by the human vision system as parallelepipeds ('boxes'). Despite their simplicity, p-images raise a number of interesting vision questions: Why are p-images seen as three dimensional objects? Why not just as flat images?; What are the dimensions and pose of the perceived objects?; Why are some p-images interpreted as rectangular boxes, while others are seen as skewed, even though there is no obvious distinction between the images?; When p-images are rotated in three dimensions, why are the image-sequences perceived as distorting objects---even though structure-from-motion would predict that rigid objects would be seen?; Why are some three dimensional parallelepipeds seen as radically different when viewed from different viewpoints? We show that these and related questions can be answered with the help of a single mathematical result and an associated perceptual principle. An interesting special case arises when there are right angles in the p-image. This case represents a singularity in the equations and is mystifying from the vision point of view, It would seem that (at least in this case) the vision system does not follow the ordinary rules of geometry but Operates in accordance with other (and as yet unknown) principles.

Descriptors :   *VISUAL PERCEPTION, *ENGINEERING DRAWINGS, OPTICAL IMAGES, BOXES, THREE DIMENSIONAL, RECTANGULAR BODIES, COMPUTER GRAPHICS, GEOMETRY, LINES(GEOMETRY), RIGHT ANGLES.

Subject Categories : Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE