Method and apparatus for selecting a prediction mode, and image encoding/decoding method and apparatus using same

摘要

The present disclosure concerns a method and apparatus for selecting an intra prediction mode and a video encoding/decoding method and apparatus using same. The encoding apparatus selects an intra prediction mode of current block to encode from input video by a variation of the value of pixel adjacent to the current block; encodes a residual block from intra-predicting the current block in the selected intra prediction mode of current block to generate coded coefficient bit having a bitstream generator for generating and outputting a bitstream including the coded coefficient bit and a prediction mode bit representing the selected intra prediction mode of current block by a macroblock or subblock unit with the prediction mode bit included selectively in the bitstream depending on the variation. Accordingly, selection process of a prediction mode for image compression is simplified, a faster compression is obtained and compressed data is deflated to improve compression efficiency.

主权项

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.