Motion-compensated adaptive wavelet filtering for image sequence processing
The paper presents new approaches in the field of motion-compensated spatio-temporal filters applied to digital image sequences. In time-varying imagery, the temporal correlation information of pixel intensities is folded by motions which may originate from both camera and object displacements. Motion-compensated filters are defined as temporal filters applied along assumed motion trajectories. As a matter of fact, the paper deals with three-dimensional spatio-temporal filters and aims at generalizing the motion-compensated temporal filtering process as the product of two distinct operators. The first operator depends only on the estimated motion parameters derived from both motion-based image segmentations and parametric affine modelings of regions in motion. The second operator analyzes only the correlations of image-by-image intensities measured along the assumed motion trajectories. Multiresolution filters or wavelets may be consequently applied along the motion trajectories to produce optimum and adaptive resulting procedures for purposes like spatio-temporal prediction, interpolation and smoothing. In the paper, applications are provided to cover the field of image sequence coding and interpolation.