A new motion compensation on a wavelet transform domain

Successive frames in a video sequence are highly correlated and they can be effectively represented by describing the inter-frame motions. Most conventional motion compensations require many calculations in the pixel domain, and this makes a difficulty in real time encoding. In this paper, we propose a simple and fast motion compensation that leads to a fast encoding. In our proposed method, all motions are described in the wavelet transform domain. The subtree coefficients that belong to a de coefficient are assumed to translate in the same direction and thus they can be represented by one motion vector (mx, my). Since one wavelet tree unit-translation in n-scale decomposition corresponds to a 2(n) pixel displacement in the pixel domain, we can describe the inter-frame motions with low cost and complexity. The error frame from the prediction is encoded by a flexible zerotree coding scheme(FZW) that permits exact bit-rate or quality controls.