Patent ID: 9641844
Date: 2017-05-02
CPC Classifications: H04N

Claim:
1. A video encoding apparatus for predicting a current block in a current frame by using an intra prediction in which the current block is predicted from one or more of first pixels in one or more of neighboring blocks located in the same current frame, comprising: a prediction mode selector configured to select an intra prediction mode of the current block depending on a pixel value variation of second pixels in the neighboring blocks, the second pixels in the neighboring blocks being located in the same current frame and adjacent to the current block, wherein the intra prediction mode indicates a prediction direction selected from a plurality of intra prediction directions to generate a predicted block of the current block when the intra prediction on the current block is performed, and wherein the second pixels to derive the pixel value variation thereof are selected in the neighboring blocks irrespective of the intra prediction mode of the current block, whereas the first pixels are selected in the neighboring blocks according to the intra prediction mode of the current block; an intra prediction encoder configured to encode a residual block, the residual block being generated by performing the intra prediction on the current block from the pixels in the neighboring blocks located in the same current frame according to the selected intra prediction mode of the current block; and a bitstream generator configured to generate a bitstream including (i) coded coefficient information of the residual block and (ii) prediction mode information, the prediction mode information representing the selected intra prediction mode of the current block by the unit of the current block or subblocks thereof, the prediction mode information being selectively encoded in the bitstream depending on the pixel value variation of the second pixels in the neighboring blocks, wherein, a preset intra prediction mode is selected as the intra prediction mode of the current block and the prediction mode information is not encoded into the bitstream, when the pixel value variation is smaller than a threshold, and the prediction mode information is encoded into the bitstream, when the pixel value variation is greater than the threshold.