Motion estimation using lapped transforms

A frequency-domain algorithm for motion estimation based on overlapped transforms of the image data is developed. The transform used is referred to as the complex lapped transform (CLT) and is formed by extending the lapped orthogonal transform to have complex basis functions. It may also be viewed as a modified short time Fourier transform. A method for estimating cross-correlation functions in the CLT domain is derived. This forms the basis of a motion estimation algorithm that calculates vectors for overlapping, windowed regions of data, with no block edge discontinuities. When combined with motion compensation also using overlapping, windowed regions, the algorithm gives prediction error energies similar to or lower than those given by conventional block matching methods