object transformation applied to the weighted center of each tile to determine the tile displacement with the pels of the tile in the present frame having the same coordinates as those resulting from the displacement the pel comparisons are carried out by the overlay comparator for luminance and or chrominance match which exceeds a predetermined limit if groups of tiles within the object are poorly matched the object may be split into two groups of tiles each group defining a potential new object the matching of pels tiles or objects may be based on absolute luminance difference absolute chrominance difference relative luminance or chrominance differences or correlations the number of close matches the sum average weighted average or other mathematical summarization of individual absolute or relative differences or a combined weighting of absolute and relative differences or correlations upon the determination of sufficiently accurate object transformations i e object transformations for which the pel matching exceeds the predetermined limit the transformations and corresponding object identifications may be sent to a parametric encoder 28 shown in fig3 the object transformations and identifications are encoded by the parametric encoder and applied therefrom through an output buffer 30 to a channel encoder 32 for transmission to the receiver 41 the transformations and identifications are received at a channel decoder 44 which applies the transformations and identifications to a parametric decoder 46 the decoded transformations and identifications are thereafter applied to the received object store 42 which reconstructs the objects in the present frame by applying the object transformations to the correspondingly identified.