IMAGE DECODER APPARATUS, IMAGE ENCODER APPARATUS AND METHOD AND PROGRAM THEREOF

摘要

A first decoding processing unit 521 obtains a difference motion vector by performing decoding of an encoded stream. A second decoding processing unit 522 obtains prediction motion vector selecting information by decoding the encoded stream. A motion vector selecting unit 525 sets candidates of the prediction motion vector as to the block to be decoded, and selects a motion vector indicated in prediction motion vector selecting information, from prediction motion vector candidates,; and an adding unit 526 calculates a motion vector of the block to be decoded by adding the difference motion vector to the prediction motion vector. The prediction motion vector is optimized, thereby improving encoding efficiency and image quality.