Discrete Wavelet Analysis for Fast Optic Flow Computation

Abstract

This paper describes an optic flow estimation method based on a discrete wavelet basis analysis. The differential optic flow equation is projected onto analytic wavelets. This gives small local linear systems (3-5 equations) that are solved to find the visual displacement. In this way, we solve the problems of time aliasing and aperture. Since the coefficients of the systems can be computed with filter banks, the estimation of a flow map costs O(N) operations (if one image of the sequence has N pixels). Our method also measures illumination changes. A convergence theorem is also stated and proved. © 2001 Academic Press.