Methods and apparatus encode image frames using intra-frame prediction by predicting pixels for a block of current pixels, based on a detected spatial pattern of pixel intensity differences among a plurality of neighboring reconstructed pixels to the block of current pixels, and encode a block of pixels of the image frame using the predicted block of reconstructed pixels. Inter-frame prediction is provided by determining whether blocks of pixels in temporally neighboring reconstructed frames corresponding to a candidate motion vector have a pattern of pixel intensity differences among the blocks from temporally neighboring frames. Predicted blocks are produced for a reconstructed frame based on the determined pattern of pixel intensity difference among temporally neighboring frames.