Patent ID: 8379725

Claim:
A motion-vector searching method for searching for a motion vector indicating a movement to an observed image of an input picture from a reference image included in said input picture as an image separated away along a time axis from said observed image by a small time difference by comparing an observed block obtained as a result of dividing said observed image with reference blocks obtained as a result of dividing said reference image into search sub-areas, said motion-vector searching method comprising: reading out observed processing blocks each included in said observed block to serve as an observed processing unit from an observation memory used for storing data of said observed image and reading out reference processing blocks included in each of said reference blocks as reference processing units from a reference memory used for storing data of said reference image; concurrently computing partial evaluation values for each of a plurality of position vectors in a search sub-area by comparing a plurality of said observed processing blocks read out from said observation memory as observed processing blocks pertaining to said observed block with a plurality of said reference processing blocks read out from said reference memory as reference processing blocks pertaining to one of said reference blocks for each of said reference blocks, such that the partial evaluation values for every position vector in the search sub-area are concurrently computed; obtaining a total evaluation value for each particular one of said position vectors as a total evaluation value associated with said particular position vector from said partial evaluation values; and finding said motion vector as an optimum position vector determined by comparison of said total evaluation values each obtained for one of said position vectors with each other; wherein: each of said reference processing blocks is shifted from a specific one of said observed processing blocks in a vertical and horizontal directions by a distance equal to one-half of a size of said observed processing block so as to place four of said reference processing blocks at such positions corresponding to positions in a vicinity of said specific observed processing block that a center of said four reference processing blocks coincides with a center of said specific observed processing block; and the total evaluation value associated with each particular one of said position vectors is obtained by summing up said partial evaluation values computed for said particular position vector by comparing each specific one of said observed processing blocks with said four reference processing blocks located in the vicinity of said specific observed processing block.