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

摘要

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.

主权项

1. A video encoding apparatus, comprising:
an intra prediction error collector configured to collect, for an intra prediction mode of a current block, prediction errors of respective blocks having the same intra prediction mode as the intra prediction mode of the current block, the respective blocks being encoded prior to encoding the current block; a transform base generator configured to generate a transform base for the intra prediction mode based on the collected prediction errors; an intra predictor configured to
predict the current block to generate a predicted block by using neighboring pixels of the current block according to the intra prediction mode of the current block, andgenerate a prediction error block of the current block according to a difference between the predicted block and the current block; and a transform encoder configured to transform the prediction error block by using the transform base for the intra prediction mode, wherein the transform base generator comprises a correlation matrix calculator configured to calculate an autocorrelation matrix for the intra prediction mode by using (i) each first matrix corresponding to each of the collected prediction errors of each of the respective blocks for the intra prediction mode and (ii) each transpose matrix of said each first matrix, wherein the autocorrelation matrix for the intra prediction mode is generated based on an average of respective multiplications of said each first matrix and said each transpose matrix of said each first matrix, and wherein the transform base for the intra prediction mode is generated based on the autocorrelation matrix for the intra prediction mode.