Image-encoding apparatus and method, transform-encoding apparatus and method, apparatus and method for generating a transform base, and image-decoding apparatus and method used in same

Abstract

A video encoding apparatus includes an intra prediction error collector; a transform base generator; an intra predictor; and a transform encoder, the intra prediction error collector collecting prediction errors of blocks having an equal intra prediction mode from macroblocks in a regular unit, which are encoded prior to a current macroblock, the transform base generator generating transform bases for respective intra prediction modes based on the prediction errors collected by the intra prediction error collector. Accordingly, the intra prediction encoding performance can be significantly improved with adding no addition information by adaptively generating a transform base according to an image characteristic change and transform-encoding an intra prediction error. As a result, the compression efficiency of a video compression apparatus or the picture quality of a reconstructed image can be greatly improved.