Method of determining search region of motion vector and motion vector detection apparatus

The present invention offers a method of determining a search region in a motion vector detection apparatus. According to this method, a search unit with a size and a ratio of height to width such that a search region made of an aggregation of the search units suitable for the configuration of the search region can be configured. In addition, a statistics amount of motion vectors that are already obtained in a vector information readout region of an original image with the position of an MB being processed as a center or in a vector information readout region in a region of a reference image with the position of an MB being processed as a center, is obtained. The appearance tendency of a motion vector is predicted by analyzing the statistics amount. The combination of search units is determined such that the search region is expanded in such a direction as to increase the occurrence probability of a motion vector for MB being processed on the basis of the obtained analysis.