Method for processing image on basis of intra prediction mode and apparatus therefor
In the present invention, a method for processing an image on the basis of an intra prediction mode and an apparatus therefor are disclosed. Particularly, the method for processing an image on the basis of an intra prediction mode may comprise the steps of: partitioning a block to be processed, on the basis of an intra prediction mode of the block to be processed; and performing intra prediction for the split block to be processed, wherein the direction in which the block to be processed is split is perpendicular to the prediction direction of the intra prediction mode of the block to be processed.
1. A method of decoding an image by a decoder, comprising:
obtaining a split flag of a processing block;
splitting the processing block into a plurality of transform units based on the split flag;
constructing reference samples for each of the transform units;
generating prediction samples of each of the transform units using the reference samples based on an intra prediction mode of the processing block; and
generating reconstruction samples of the processing block based on the prediction samples,
wherein the reference samples comprise a sample neighboring a left boundary of each of the transform units, a sample neighboring a top boundary of each of the transform units and a sample neighboring a top left of each of the transform units, and
wherein generating prediction samples of each of the transform units further comprises:
obtaining a filtering flag of the reference samples based on the intra prediction mode; and
filtering the reference samples based on the filtering flag.
2. The method of claim 1 , wherein a split direction of the processing block is horizontal or vertical.
3. The method of claim 2 , whether the processing block is split according to a square quad-tree method or split vertically to the prediction direction is determined based on the intra-prediction mode of the processing block.
4. The method of claim 3 , wherein the processing block is split according to the square quad-tree method if the intra-prediction mode of the processing block is intra-planar or intra-DC, otherwise the processing block is split vertically to the prediction direction.
5. The method of claim 1 , further comprising:
reconstructing a transform unit into a square block; and
performing inverse transform on the reconstructed processing block.
6. The method of claim 1 , wherein a number of the reference samples is determined based on a size of a split transform unit.
7. A method of encoding an image by an encoder, comprising:
splitting a processing block into a plurality of transform units;
generating a split flag of the processing block;
constructing reference samples for each of the transform units;
generating prediction samples of each of the transform units using the reference samples based on the intra-prediction mode of the processing block; and
generating residual samples of the processing block based on the prediction samples,
wherein the reference samples comprise a sample neighboring a left boundary of each of the transform units, a sample neighboring a top boundary of each of the transform units and a sample neighboring a top left of each of the transform units, and
wherein generating prediction samples of each of the transform units further comprises:
filtering the reference samples; and
generating a filtering flag of the reference samples based on the intra prediction mode.
8. The method of claim 7 , wherein a split direction of the processing block is horizontal or vertical.
9. The method of claim 8 , wherein whether the processing block is split according to a square quad-tree method or split vertically to the prediction direction is determined based on the intra-prediction mode of the processing block.
10. The method of claim 7 , wherein a number of the reference samples is determined based on a size of a split transform unit.
11. A non-transitory decoder-readable medium for storing a bitstream generated by the method according to claim 7 .
12. A transmission method for data comprising a bitstream for an image, the method comprising:
obtaining the bitstream for the image; and
transmitting the data of the bitstream,
wherein the bitstream is generated by performing the steps of:
splitting a processing block into a plurality of transform units;
generating a split flag of the processing block;
constructing reference samples for each of the transform units;
generating prediction samples of each of the transform units using the reference samples based on the intra-prediction mode of the processing block; and
generating residual samples of the processing block based on the prediction samples,
wherein the reference samples comprise a sample neighboring a left boundary of each of the transform units, a sample neighboring a top boundary of each of the transform units and a sample neighboring a top left of each of the transform units, and
wherein generating prediction samples of each of the transform units further comprises:
filtering the reference samples; and
generating a filtering flag of the reference samples based on the intra prediction mode.