Patent ID: 8472083
Filing Date: 2013-06-25
Classification: H04N

Abstract:
1. An intra prediction apparatus for performing intra predictions of a picture, the apparatus comprising: an intra prediction unit configured to perform the intra predictions of the picture according to (a) a first intra prediction mode for performing an intra prediction for each of first blocks obtained by dividing the picture, and (b) a second intra prediction mode for performing an intra prediction for each of second blocks obtained by dividing the first block; and a control unit configured to cause said intra prediction unit to alternately perform, within the first block, (i) the intra prediction according to the second intra prediction mode on pixel values read out from a corresponding one of the second blocks, and (ii) a portion of the intra prediction according to the first intra prediction mode on the pixel values of the corresponding one of the second blocks which has already been subjected to the intra prediction (i), and to output predicted pixel values to a subtractor for calculating differences between the predicted pixel values with respect to the corresponding one of the second blocks and pixel values to be coded, wherein: a control unit is configured to cause said intra prediction unit to perform sets of intra predictions for each of the first blocks, each of the sets is composed of the intra prediction (i) and the intra prediction (ii), the sets of intra predictions for each of the first blocks are sequentially performed in units of the second block and completed when the last set of the intra prediction according to the second intra prediction mode on the last second block and the intra prediction according to the first intra prediction mode on a part which is of the first block and corresponds to the last second block is completed, and the portion of the intra prediction according to the first intra prediction mode is performed for each of the second blocks and a corresponding part of the first block.