Abstract: A device or method for video compression uses a technique in which changes in the image are encoded by motions of block of the image and signals indicating evolutions in the block. To determine the motions of the blocks of a each frame, a search is performed for a similar block of a previous frame based on points of the previous frame which are arranged in successive diamond shaped zones. The diamond shaped zones may be centred on the position of the block in previous frame, or one or more predicted motions of the block. The method terminates according to criteria defined using thresholds.

Abstract: This processor is capable of real time processing of blocks of video pixel or other two-dimensional data to yield the two-dimensional Discrete Cosine Transform (DCT) thereof. The processor can be used as part of a video bandwidth or image compression system. The circuitry comprises a first one-dimensional DCT processor which simultaneously computes an entire row or column of vector inner products by using distributed arthmetic and using decimation-in-frequency to reduce the amount of memory capacity (ROM) required. Partial sums may also be used to further reduce ROM size. The one-dimensional transformed matrix from the first processor is stored in a transposition memory and the transpose of the stored matrix is applied to a second one-dimensional DCT processor of similar circuitry which computes the desired two-dimensional DCT of the input data matrix.