Method and device for deriving a prediction sample in decoding/encoding video signal using binary and quad trees
Provided are a method and a device for decoding a video signal to provide stereographic image content with high resolution. For decoding a video signal, an intra prediction mode of a current block is determined, and a prediction sample is obtained by performing intra prediction of the current block based on the intra prediction mode.
1. A method for decoding a video, the method comprising:
determining a prediction mode of a current block, prediction modes comprising intra prediction and inter prediction; and
obtaining a prediction sample of the current block based on the determined prediction mode,
wherein the current block is generated by splitting a coding block based on at least one of a quad tree or a binary tree,
wherein determination of whether to split the coding block based on the binary tree is performed after it is determined that the coding block is not split based on the quad tree,
wherein when the prediction mode of the current block indicates the inter prediction, the prediction sample of the current block is obtained based on a weighted sum operation of a first sample and a second sample of the current block, the first sample being obtained by performing inter prediction for the current block and the second sample being derived by using at least one reference sample adjacent to the current block, and
wherein a set of weights applied to the first sample and the second sample is determined based on whether the prediction mode of a neighboring block adjacent to the current block is the inter prediction or the intra prediction.
2. The method of claim 1 , wherein when the prediction mode of the current block indicates the intra prediction, the prediction sample of the current block is obtained by correcting an intra predicted sample using a neighboring sample adjacent to the current block, the intra predicted sample being obtained based on an intra prediction mode of the current block, and
wherein when the intra prediction mode of the current block has a top-right diagonal direction, the correction is performed by using a neighboring sample lying on a bottom-left diagonal direction from the intra predicted sample.
3. The method of claim 1 , wherein the prediction sample of the current block is obtained by using a downsampled neighboring sample of the current block, the prediction sample and the downsampled neighboring sample being the same color component, and
wherein a sampling rate of the current block is determined based on a size of the current block.
4. The method of claim 1 , wherein the set of weights is determined among a plurality of candidate sets, and
wherein the candidate sets comprise a set of (½, ½) and a set of (¼, ¾).
5. A device for decoding a video, the device comprising:
one or more processors configured to:
split a coding block based on at least one of a quad tree or a binary tree, a current block being one of partitions generated by splitting the coding block;
determine a prediction mode of the current block, prediction modes comprising intra prediction and inter prediction;
obtaining a prediction sample of the current block based on the determined prediction mode,
wherein determination of whether to split the coding block based on the binary tree is performed after it is determined that the coding block is not split based on the quad tree,
wherein when the prediction mode indicates the inter prediction, the prediction sample of the current block is obtained based on a weighted sum operation of a first sample and a second sample of the current block,
wherein a set of weights applied to the first sample and the second sample is determined based on whether the prediction mode of a neighboring block adjacent to the current block is the inter prediction or the intra prediction.
6. The device of claim 5 , wherein when the prediction mode of the current block indicates the intra prediction, the prediction sample of the current block is obtained by correcting an intra predicted sample using a neighboring sample adjacent to the current block, and
wherein when the intra prediction mode of the current block has a top-right diagonal direction, the correction is performed by using a neighboring sample lying on a bottom-left diagonal direction from the intra predicted sample.
7. The device of claim 5 , wherein the prediction sample of the current block is obtained by using a downsampled neighboring sample of the current block, the prediction sample and the downsampled neighboring sample being the same color component, and
wherein a sampling rate of the current block is determined based on a size of the current block.
8. A method for encoding a video, the method comprising:
determining a prediction mode of a current block, prediction modes comprising intra prediction and inter prediction; and
obtaining a prediction sample of the current block based on the determined prediction mode,
wherein the current block is generated by splitting a coding block based on at least one of a quad tree or a binary tree,
wherein determination of whether to split the coding block based on the binary tree is performed after it is determined that the coding block is not split based on the quad tree,
wherein when the prediction mode of the current block indicates the inter prediction, the prediction sample of the current block is obtained based on a weighted sum operation of a first sample and a second sample of the current block, the first sample being obtained by performing inter prediction for the current block and the second sample being derived by using at least one reference sample adjacent to the current block, and
wherein a set of weights applied to the first sample and the second sample is determined based on whether the prediction mode of a neighboring block adjacent to the current block is the inter prediction or the intra prediction.
9. The method of claim 8 , wherein when the prediction mode of the current block indicates the intra prediction, the prediction sample of the current block is obtained by correcting an intra predicted sample using a neighboring sample adjacent to the current block, the intra predicted sample being obtained based on an intra prediction mode of the current block, and
wherein when the intra prediction mode of the current block has a top-right diagonal direction, the correction is performed by using a neighboring sample lying on a bottom-left diagonal direction from the intra predicted sample.
10. The method of claim 8 , wherein the prediction sample of the current block is obtained by using a downsampled neighboring sample of the current block, the prediction sample and the downsampled neighboring sample being the same color component, and
wherein a sampling rate of the current block is determined based on a size of the current block.
11. A device for encoding a video, the device comprising:
one or more processors configured to:
split a coding block based on at least one of a quad tree or a binary tree, a current block being one of partitions generated by splitting the coding block;
determine a prediction mode of the current block, prediction modes comprising intra prediction and inter prediction;
obtaining a prediction sample of the current block based on the determined prediction mode,
wherein determination of whether to split the coding block based on the binary tree is performed after it is determined that the coding block is not split based on the quad tree,
wherein when the prediction mode indicates the inter prediction, the prediction sample of the current block is obtained based on a weighted sum operation of a first sample and a second sample of the current block,
wherein a set of weights applied to the first sample and the second sample is determined based on whether the prediction mode of a neighboring block adjacent to the current block is the inter prediction or the intra prediction.
12. The device of claim 11 , wherein when the prediction mode of the current block indicates the intra prediction, the prediction sample of the current block is obtained by correcting an intra predicted sample using a neighboring sample adjacent to the current block, and
wherein when the intra prediction mode of the current block has a top-right diagonal direction, the correction is performed by using a neighboring sample lying on a bottom-left diagonal direction from the intra predicted sample.