Encoding device and method, decoding device and method, and recording medium

摘要

A device and method of the present invention aims to improve encoding efficiency. A low level picture is encoded based on predetermined picture elements in an input picture. Picture elements of a middle level picture are half the picture elements of the input picture. The other half of the picture elements are occupied by the low level picture. Because the low level picture has been already encoded, upon encoding the middle level picture, the picture elements which must be actually encoded are only half the picture elements of the middle level picture. Picture elements of a high level picture are an entire of the input picture elements. Half of them are picture elements of the middle level picture or low level picture. Because the low level picture and the middle level picture have been already encoded, the picture elements which must be actually encoded to encode the high level picture are only half the picture elements of the high level picture.