Method and apparatus for encoding and decoding video signal using intra prediction filtering

1. A method for decoding a video signal by an apparatus, the method comprising:

generating a first prediction block based on a prediction mode of a current block;

checking a prediction mode of a neighboring block adjacent to the current block;

generating a second prediction block based on the prediction mode of the neighboring block;

generating a final prediction block based on applying a weight to the first prediction block and the second prediction block; and

reconstructing the video signal based on the final prediction block,

wherein the weight is determined based on a similarity between the prediction mode of the current block and the prediction mode of the neighboring block.

2. The method of claim 1 , wherein the checking further includes

checking whether an upper neighboring block adjacent to an upper boundary of the current block and/or a left neighboring block adjacent to a left boundary is present, and

checking whether the upper neighboring block and/or the left neighboring block is available.

3. The method of claim 2 , wherein whether the upper neighboring block and/or the left neighboring block is available is determined based on whether the prediction mode of the upper neighboring block and/or the left neighboring block is the same as the prediction mode of the current block.

4. The method of claim 1 , wherein when a plurality of neighboring blocks is present, the prediction mode of the neighboring block is set as one representative mode based on a specific criterion.

5. The method of claim 4 , wherein the specific criterion is determined based on at least one of a position of the neighboring block, a most probable prediction mode, an intermediate prediction mode, or a block size.

6. The method of claim 1 , wherein in the generating of the second prediction block, when a reference sample is not available, the second prediction block is generated based on the reference sample at another position.

7. The method of claim 1 , wherein the weight applied to the second prediction block has a larger weight value as being closer to a boundary of a block.

8. The method of claim 1 , wherein based on the similarity between the prediction mode of the current block and the prediction mode of the neighboring block is equal to or more than a specific value, the weight of the current block is set to be higher than the neighboring block, and

wherein based on the similarity between the prediction mode of the current block and the prediction mode of the neighboring block is less than the specific value, the weight of the neighboring block is configured to be higher than the current block.

9. The method of claim 1 , further comprising:

obtaining a boundary filtering flag representing whether boundary filtering is performed at a specific level,

wherein the checking is performed based on the boundary filtering is performed at the specific level according to the boundary filtering flag.

10. An apparatus for decoding a video signal, the apparatus comprising:

a processor configured to

generate a first prediction block based on a prediction mode of a current block,

check a prediction mode of a neighboring block adjacent to the current block,

generate a second prediction block based on the prediction mode of the neighboring block,

generate a final prediction block based on applying a weight to the first prediction block and the second prediction block, and

reconstruct the video signal based on the final prediction block,

wherein the weight is determined based on a similarity between the prediction mode of the current block and the prediction mode of the neighboring block.

11. The apparatus of claim 10 , wherein when the prediction mode of the neighboring block is the same as the prediction mode of the current block, the second prediction block is generated based on the prediction mode of the neighboring block.

12. The apparatus of claim 10 , wherein when a plurality of neighboring blocks is present, the prediction mode of the neighboring block is set as one representative mode based on a specific criterion.

13. The apparatus of claim 10 , wherein the processor is further configured to

obtain a boundary filtering flag representing whether boundary filtering is performed at a specific level.

14. An apparatus for encoding a video signal, the apparatus comprising:

a processor configured to

generate a first prediction block based on a prediction mode of a current block,

check a prediction mode of a neighboring block adjacent to the current block,

generate a second prediction block based on the prediction mode of the neighboring block,

generate a final prediction block based on applying a weight to the first prediction block and the second prediction block, and

encode the video signal based on the final prediction block,

wherein the weight is determined based on a similarity between the prediction mode of the current block and the prediction mode of the neighboring block.