IMAGE ENCODER, IMAGE ENCODING METHOD, AND IMAGE ENCODING PROGRAM

摘要

PROBLEM TO BE SOLVED: To improve encoding efficiency while suppressing an increase in a circuit scale and throughput.SOLUTION: An intra-prediction mode selection section 310 selects an intra-prediction mode for a coding target block from among a plurality of intra-prediction mode candidates. An encoding section encodes an encoding target block, a residual signal calculated from a prediction block generated on the basis of the selected intra-prediction mode, and a value that indicates the selected intra-prediction mode. The intra-prediction mode selection section 310 specifies one intra-prediction mode candidate by applying a hierarchical search for gradually performing a search while narrowing down a thinning-out interval and a search range to the plurality of intra-prediction mode candidates.