Image encoder, image decoder, image encoding method, and image decoding method

摘要

The image coding apparatus is constituted comprising an atom extraction section 109 for acquiring position data indicating the positions of atoms of prediction residual data in macroblocks, for each of the macroblocks; and a variable length encoding section 113 for determining the frequency of occurrence distribution of the position data in the macroblocks to be encoded, in accordance with the number of atoms of prediction residual data present in the macroblocks, and for performing arithmetic coding of the position data on the basis of the frequency of occurrence distribution thus determined. An improvement in the efficiency of the entropy coding of the atom parameters of Matching Pursuits coding is therefore feasible.