Image encoding/decoding method and device, and recording medium storing bitstream
An image encoding/decoding method and apparatus for performing template matching-based intra prediction are provided. An image decoding method may comprise deriving a first intra-prediction mode for a current block, generating a first intra-prediction block corresponding to the first intra-prediction mode, deriving a second intra-prediction mode for the current block, generating a second intra-prediction block corresponding to the second intra-prediction mode, and generating a final intra-prediction block by using a weighted sum of the first intra-prediction block and the second intra-prediction block.
1. An image decoding method performed by an image decoding apparatus, the method comprising:
determining whether a combination of an intra prediction and an inter prediction is used for prediction on a current block; and
in response to that the combination of the intra prediction and the inter prediction is used for prediction on the current block, generating a final prediction block of the current block,
wherein, generating of the final prediction block of the current block comprises:
generating a first prediction block of the current block by performing intra prediction for the current block based on an intra prediction mode and reference samples of a reference sample line;
generating a second prediction block of the current block by performing inter prediction for the current block using a merge index; and
generating the final prediction block of the current block based on the first prediction block and the second prediction block,
wherein when the combination of the intra prediction and the inter prediction is applied for prediction on the current block, the intra prediction mode and the reference sample line are determined without obtaining information on intra prediction regarding the intra prediction mode and the reference sample line,
wherein the intra prediction mode of the current block is fixed as planar mode and the reference sample line is fixed as a first reference sample line adjacent to the current block.
2. The method of claim 1 ,
wherein, the second prediction block of the current block is generated by a merge mode.
3. The method of claim 1 ,
wherein the final prediction block of the current block is generated by a weighted sum of the first prediction block and the second prediction block.
4. The method of claim 3 ,
wherein weights used for the weighted sum comprise a first weight which is applied to the first prediction block and a second weight which is applied to the second prediction block, and
wherein a sum of the first weight and the second weight is 4.
5. The method of claim 1 ,
wherein the combination of the intra prediction and the inter prediction is used for prediction on the current block based on a slice type of the current block.
6. An image encoding method performed by an image encoding apparatus, the method comprising:
determining whether a combination of an intra prediction and an inter prediction is used for prediction on a current block; and
in response to that the combination of the intra prediction and the inter prediction is used for prediction on the current block, generating a final prediction block of the current block,
wherein, generating of the final prediction block of the current block comprises:
generating a first prediction block of the current block by performing intra prediction for the current block based on an intra prediction mode and reference samples of a reference sample line;
generating a second prediction block of the current block by performing inter prediction for the current block using a merge index; and
generating the final prediction block of the current block based on the first prediction block and the second prediction block,
wherein when the combination of the intra prediction and the inter prediction is applied for prediction on the current block, the intra prediction mode and the reference sample line are determined without obtaining information on intra prediction regarding the intra prediction mode and the reference sample line,
wherein the intra prediction mode of the current block is fixed as planar mode and the reference sample line is fixed as a first reference sample line adjacent to the current block.
7. The method of claim 6 ,
wherein, the second prediction block of the current block is generated by a merge mode.
8. The method of claim 6 ,
wherein the final prediction block of the current block is generated by a weighted sum of the first prediction block and the second prediction block.
9. The method of claim 8 ,
wherein weights used for the weighted sum comprise a first weight which is applied to the first prediction block and a second weight which is applied to the second prediction block, and
wherein a sum of the first weight and the second weight is 4.
10. The method of claim 6 ,
wherein, in response to that the combination of the intra prediction and the inter prediction is used for prediction on the current block, the reference sample for the intra prediction of the current block is determined based on a first reference sample line adjacent to the current block among a plurality of reference sample lines.
11. The method of claim 6 ,
wherein the combination of the intra prediction and the inter prediction is used for prediction on the current block based on a slice type of the current block.
12. A non-transitory computer-readable recording medium storing a bitstream which is generated by an image encoding method,
wherein the image encoding method comprises
determining whether a combination of an intra prediction and an inter prediction is used for prediction on a current block; and
in response to that the combination of the intra prediction and the inter prediction is used for prediction on the current block, generating a final prediction block of the current block,
wherein, generating of the final prediction block of the current block comprises:
generating a first prediction block of the current block by performing intra prediction for the current block based on an intra prediction mode and reference samples of a reference sample line;
generating a second prediction block of the current block by performing inter prediction for the current block using a merge index; and
generating the final prediction block of the current block based on the first prediction block and the second prediction block,
wherein when the combination of the intra prediction and the inter prediction is applied for prediction on the current block, the intra prediction mode and the reference sample line are determined without obtaining information on intra prediction regarding the intra prediction mode and the reference sample line,
wherein the intra prediction mode of the current block is fixed as planar mode and the reference sample line is fixed as a first reference sample line adjacent to the current block.