Discrete formulation of pel-recursive motion compensation with recursive least squares updates

A new class of motion-compensating estimators, based on a discrete formulation of pel-recursive motion compensation, is studied. This class of four-dimensional predictors is more general than the bilinear interpolation, which is used in typical pel-recursive algorithms. The operators performing the estimation are obtained through a least squares solution, both with and without weighting, of a set of linear equations relating the intensity of pixels in a causal neighborhood to pixels in the past frame. In the proposed method, the displaced luminance, and not the motion, is computed directly. The operators´ performance is compared with the standard pel-recursive techniques, and it is found that the proposed estimators perform better than the standard methods, particularly in areas of large displacement. Some computational issues are discussed, and an implementation utilizing recursive least squares with QR decomposition is proposed.<>