Video encoding and decoding method
Disclosed are a method and apparatus for improving the accuracy of intra-prediction in order to improve encoding and decoding efficiency. The video decoding method may improve the prediction efficiency for the current pixel to be predicted by referring to the degree of variation in surrounding pixels, to thereby effectively decode the bit stream with improved encoding efficiency. In addition, an additional prediction candidate is used to achieve improved accuracy of intra-prediction, and the thus-improved accuracy of intra-prediction may reduce residual components and improve encoding efficiency. Further, an improved planar mode is utilized to achieve improved intra-prediction.
1. A video decoding method comprising:
decoding received bit stream to generate reconstruction information including a residual value for a current pixel and intra-prediction information;
generating a prediction value for the current pixel using a pixel T belonging to a block adjacent to an upper right corner and a pixel L belonging to a block adjacent to a lower left corner of a current block based on the intra-prediction information; and,
adding the residual value for the current pixel to the prediction value to generate a reconstructed image,
wherein the generating the prediction value further comprises:
generating a first prediction value using a first reference pixel and the pixel T;
generating a second prediction value using a second reference pixel and the pixel L; and
generating the prediction value for the current pixel using the first prediction value and the second prediction value,
wherein the generating the prediction value comprises applying weights to the first prediction value and the second prediction value, and
wherein the current block is partitioned into at least two regions, and intra-prediction is sequentially performed for each partitioned region.
2. The video decoding method of claim 1 ,
wherein the pixel T is any one of a pixel TR closest to the current block in the block, a pixel selected from among pixels positioned in the same horizontal line as the pixel TR, and a pixel generated by filtering the pixels positioned in the same horizontal line as the pixel TR, and
wherein the pixel L is any one of a pixel LB closest to the current block in the block, a pixel selected from among pixels positioned in the same vertical line as the pixel LB, and a pixel generated by filtering the pixels positioned in the same vertical line as the pixel LB.
3. The video decoding method of claim 1 ,
wherein the first reference pixel is a pixel positioned in the same horizontal line as the current pixel and adjacent to the current block, and
wherein the second reference pixel is a pixel positioned in the same vertical line as the current pixel and adjacent to the current block.
4. The video decoding method of claim 1 ,
wherein the generating of the first prediction value includes generating the first prediction value by applying weights to the pixel TR and the pixel positioned in the same horizontal line as the current pixel and adjacent to the current block, and
wherein the generating of the second prediction value includes the second prediction value by applying weights to the pixel LB and the pixel positioned in the same vertical line as the current pixel and adjacent to the current block.
5. The video decoding method of claim 4 , wherein each weight is determined based on a direction of the current block.
6. The video decoding method of claim 5 , wherein the direction of the current block is divided into a horizontal direction and a vertical direction.
7. The video decoding method of claim 1 , wherein the prediction value is generated by averaging the first prediction value and the second prediction value.