Relaxing the Brightness Constancy Assumption in Computing Optical Flow

Abstract

Optical flow is the apparent (or perceived) motion of image brightness patterns arising from relative motion of objects and observer. Estimation of the optical flow requires the application of two kinds of constraint: the flow field smoothness constraint and the brightness constancy constraint. The brightness constancy constraint permits one to match image brightness values across images, but is very restrictive. We propose replacing this constraint with a more general constraint, which permits a linear transformation between image brightness values. The transformation parameters are allowed to vary smoothly so that inexact matching is allowed. We describe the implementation on a highly parallel computer and present sample results.