ENCODER AND METHOD, AND DECODER AND METHOD

摘要

PROBLEM TO BE SOLVED: To provide an encoder and a decoder capable of efficiently encoding/ decoding position information of a leaf or a node in spite of a small number of bits. SOLUTION: The encoder includes; a branch layer discrimination section 104 for deciding at which layer a leaf or a node and a preceding left or a preceding node are branched; and a position information encoding section 105 for outputting a code corresponding to a layer at which the layer branches as a position information code of the leaf or the node, and for encoding only information at which order number of layer the one preceding left or node and the current leaf or node are branched as the leaf or node position information so as to attain efficient encoding.