Method and apparatus for image encoding/decoding
A method and an apparatus for image encoding/decoding are disclosed. The apparatus includes: a block decomposer for decomposing a current block into a plurality of sub-blocks; and an intra prediction encoder for performing an intra prediction encoding by referring to already encoded and decoded adjacent pixel information of each sub-block, based on an intra prediction mode equal to an intra prediction mode of the current block, thereby generating a bit stream for the current block. In image encoding and image decoding, when a current block to be encoded or decoded is predicted, the disclosed method and apparatus can improve the accuracy of the prediction, which can provide an image with a satisfactory reproduction quality by improved coding efficiency.
1. A video decoding method using an intra prediction, the method comprising:
obtaining mode information of a current block from a bitstream;
selecting an intra prediction mode of the current block from among a plurality of intra prediction modes, based on the obtained mode information;
identifying a plurality of sub-blocks of the current block when the current block includes the plurality of sub-blocks respectively corresponding to transform blocks of the current block; and
reconstructing the plurality of sub-blocks based on respectively predicting the plurality of sub-blocks by using neighboring pixels adjacent to each of the plurality of sub-blocks, wherein each of the plurality of sub-blocks is predicted by using the same intra prediction mode of the current block selected based on the obtained mode information,
wherein the reconstructing of the plurality of sub-blocks comprises:
predicting one of the plurality of sub-blocks;
reconstructing a residual sub-block corresponding to the predicted sub-block by decoding the bitstream; and
adding the predicted sub-block to the reconstructed residual sub-block to thereby reconstruct the sub-block,
wherein one or more pixels in the reconstructed sub-block are used as part of the neighboring pixels for predicting at least one non-reconstructed sub-block adjacent to the reconstructed sub-block.
2. The method of claim 1 , wherein the neighboring pixels are located at a left side or an upper side of each of the plurality of sub-blocks.
3. The method of claim 1 , wherein the neighboring pixels are pixels which have been already decoded and reconstructed.