Image coding apparatus and image coding method

摘要

An image coding apparatus and an image coding method are provided for reducing arithmetic processing while keeping a high compression ratio. A coding process necessary for the bi-prediction motion search can be effectively reduced by determining a block size for a bi-prediction motion search or a center position for a motion search on the basis of a result of a motion search of a unidirectional prediction. Further, a compression ratio can be also kept as high as possible, because the block size or the center position are obtained on the basis of the result of the motion search of the unidirectional prediction.