Apparatus and method for detecting motion vectors in a frame decimating video encoder.

A motion estimating method serves to determine a set of target motion vectors between a current and its previous selected frames, wherein N number of frames are skipped between the current and the previous selected frames, said N being a positive integer inclusive of 1. This method is implemented through the use of all frames, i.e., the current and the previous selected frames and the N number of skipped frames in order to obtain a series of motion vectors for one of the search blocks within the current selected frame. Said series of motion vectors is then summed up to define a target motion vector representing the displacement between said one of the search blocks and the corresponding best matching block in the previous selected frame. The process is repeated until the set of target motion vectors for all of the search blocks contained in the current selected frame are detected.