The Incremental Rigidity Scheme for Recovering Structure from Motion: Position versus Velocity Based Formulations

Perceptual studies suggest that the visual system uses the rigidity assumption to recover three dimensional structure from motion. Ullman (1984) recently proposed a computational scheme, the incremental rigidity scheme, which uses the rigidity assumption to recover the structure of rigid and nonrigi...

Full description

Saved in:
Bibliographic Details
Main Authors: Grzywacz, Norberto M, Hildreth, Ellen C
Format: Report
Language:English
Subjects:
Anatomy and Physiology
COMPUTATIONS
COMPUTER AIDED DIAGNOSIS
ESTIMATES
FORMULATIONS
HUMANS
LONG RANGE(TIME)
MOVING TARGETS
OPTICAL IMAGES
PERCEPTION
Psychology
RECOVERY
RIGIDITY
ROUGHNESS
SPACE PERCEPTION
THEORY
THREE DIMENSIONAL
VELOCITY
VISION
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Perceptual studies suggest that the visual system uses the rigidity assumption to recover three dimensional structure from motion. Ullman (1984) recently proposed a computational scheme, the incremental rigidity scheme, which uses the rigidity assumption to recover the structure of rigid and nonrigid objects in motion. The scheme assumes the input to be discrete positions of elements in motion, under orthographic projection. We present formulations of Ullman's method that use velocity information and perspective projection in the recovery of structure. Theoretical and computer analyses show that he velocity based formulations provide a rough estimate of structure quickly, but are not robust over an extended time period. The stable long term recovery of structure requires disparate views of moving objects. Our analysis raises interesting questions regarding the recovery of structure from motion in the human visual system. Keywords: Space perception.