ENCODING DEVICE AND METHOD, AND DECODING DEVICE AND METHOD

摘要

It is possible to provide an encoding device and a method and a decoding device and a method which can suppress lowering of the compression efficiency. When an adjacent block adjacent to a target block as an image encoding object is encoded by a second encoding method which is different from a first encoding method, an alternative block detection unit (64) detects as an alternative block among the blocks encoded by the first encoding method, a peripheral block positioned at a distance within a threshold value from the target block or at a distance within a threshold value from an adjacent block with respect to the direction connecting the target block and the adjacent block. A first encoding unit (63) encodes the target block by the first encoding method by using the alternative block detected by the detection unit. A second encoding unit (66) encodes the target block not encoded by the first encoding method, by using the second encoding method.