TABLE-DRIVEN BI-DIRECTIONAL MOTION ESTIMATION USING SCRATCH AREA AND OFFSET VALUES

A prediction block is generated using a first region of a first reference frame and a second region of a second reference frame. A current block of a current frame is compared to the prediction block, where the comparison is based on a set of match points from the current block and a corresponding set of match points from the prediction block. The current block is processed based on the comparison of the current block to the prediction block. For each match point of the prediction block, a table index is generated from a pixel of the first region and either a pixel of the second region or an offset value, and a corresponding entry is retrieved from a lookup table using the table index. The comparison of the current block to the prediction block is based on the lookup-table entries for the prediction block. In a preferred embodiment, prediction blocks are generated for motion-estimation processing for bi-directionally predicted (B) frames of certain video encoding standards such as the H.263 standard.