摘要 |
A search window of data blocks of a reference (viz., previous) frame is established in a search window memory for preparation for estimating displacement of a current data block of a current picture frame within the search window. The search window memory has memory capacity of two times that of the search window. The current picture frame is divided, in horizontal and vertical directions, into a plurality of data blocks which are sequentially written in a current block memory along each of horizontal lines according to a predetermined order of horizontal lines. A reference frame memory is accessed for writing data blocks in the search window memory for completing a search window for a current data block on a given horizontal line and further accessing the reference frame memory for writing another data blocks for preparing a part of a search window for a data block located on a horizontal line next to said given horizontal line when the current data block belongs to one of a predetermined number of last data blocks on said given horizontal line. On the other hand, the reference frame memory is accessed for writing data blocks in the search window memory for completing a search window for the current data black when the current data is located on the given horizontal line and outside of the predetermined number of last data blocks. <MATH> |