Abstract: Pictorial information is encoded using an interframe prediction technique which accounts for spatial and/or temporal changes in illumination. In one embodiment (FIG. 3), the intensity value of each element of a picture is predicted using the intensity of the corresponding element in a previous frame and a recursively updated gain factor .rho. which can account for both illumination changes as well as object movement. The prediction error and pel location is encoded only if the error exceeds a predetermined threshold. In a second embodiment (FIG. 3), additional predictions are made using displacement compensated prediction alone and in combination with gain adjustment. The best predictor is selected and the corresponding prediction error transmitted only if it is large.

Abstract: Propagation of transmission errors in adaptively predicted, DPCM encoded video signals is reduced by including a leak circuit (114) in the encoder (FIG. 1). The leak circuit modifies each prediction in response to local characteristics in the area of the picture being encoded.

Abstract: Video signals are encoded (FIG. 5) using motion compensated prediction which operates on a transform domain representation of the signal. The displacement estimate used for compensation is recursively updated, so that a feedback path exists between the output (205) of the displacement calculator and one of its output (209). The update term is also computed in the transform domain. A decoder (FIG. 6) uses the same prediction technique to recover the original picture.