Video signal processing method using intra prediction and device therefor
A video signal processing method comprises the steps of: parsing a first syntax element indicating whether to activate a DIMD mode, wherein the first syntax element is signaled on a sequence parameter set (SPS) raw byte sequence payload (RBSP) syntax; when the first syntax element indicates activation of the DIMD mode, parsing a second syntax element indicating whether the DIMD mode is applied to a current block; and when the second syntax element indicates that the DIMD mode is applied to the current block, reconstructing the current block on the basis of the DIMD mode.
1 . A video signal decoding device comprising
a processor,
wherein the processor is configured to:
parse a first syntax element indicating whether a decoder side intra mode derivation (DIMD) mode is enabled, the first syntax element being signaled on a sequence parameter set (SPS) raw byte sequence payload (RBSP) syntax;
when the first syntax element indicates the DIMD mode is enabled,
when a color component of a current block is a luma component and an inter prediction is not applied to the current block, parse a second syntax element indicating whether the DIMD mode is applied to the current block; and
when the second syntax element indicates the DIMD mode is applied to the current block, reconstruct the current block based on the DIMD mode.
2 . The video signal decoding device of claim 1 , wherein the processor is configured to:
obtain directional information of neighboring blocks of the current block;
select, from the directional information, first directional information which most frequently occurs and second directional information which second most frequently occurs; and
reconstruct the current block based on the first directional information and the second directional information.
3 . The video signal decoding device of claim 2 , wherein the current block is reconstructed based on a weight value corresponding to the first directional information and a weight value corresponding to the second directional information.
4 . The video signal decoding device of claim 2 , wherein the current block is reconstructed using a first prediction mode and a derived intra-prediction mode generated based on the first directional information and the second directional information, and
the first prediction mode is a planar mode.
5 . The video signal decoding device of claim 4 , wherein the current block is reconstructed based on prediction modes included in a most probable mode (MPM) list, and
the MPM list is constructed based on the directional information of the neighboring blocks of the current block.
6 . The video signal decoding device of claim 5 , wherein the current block is reconstructed based on a combination of the derived intra-prediction mode and one of the prediction modes included in the MPM list.
7 . A video signal encoding device comprising
a processor,
wherein the processor is configured to;
obtain a bitstream to be decoded by a decoder using a decoding method, the decoding method comprising:
parsing a first syntax element indicating whether a decoder side intra mode derivation (DIMD) mode is enabled, the first syntax element being signaled on a sequence parameter set (SPS) raw byte sequence payload (RBSP) syntax;
when the first syntax element indicates the DIMD mode is enabled,
when a color component of a current block is a luma component and an inter prediction is not applied to the current block, parsing a second syntax element indicating whether the DIMD mode is applied to the current block; and
when the second syntax element indicates the DIMD mode is applied to the current block, reconstructing the current block based on the DIMD.
8 . The video signal encoding device of claim 7 , wherein the reconstructing of the current block based on the DIMD mode comprises:
obtaining directional information of neighboring blocks of the current block;
selecting, from the directional information, first directional information which most frequently occurs and second directional information which second most frequently occurs; and
reconstructing the current block based on the first directional information and the second directional information.
9 . The video signal encoding device of claim 7 , wherein the current block is reconstructed based on a weight value corresponding to the first directional information and a weight value corresponding to the second directional information.
10 . The video signal encoding device of claim 7 , wherein the current block is reconstructed using a first prediction mode and a derived intra-prediction mode generated based on the first directional information and the second directional information, and
the first prediction mode is a planar mode.
11 . The video signal encoding device of claim 10 , wherein the current block is reconstructed based on prediction modes included in a most probable mode (MPM) list, and
the MPM list is constructed based on the directional information of the neighboring blocks of the current block.
12 . The video signal encoding device of claim 11 , wherein the current block is reconstructed based on a combination of the derived intra-prediction mode and one of the prediction modes included in the MPM list.
13 . A method for obtaining a bitstream, the method comprising:
obtaining a first syntax element indicating whether a decoder side intra mode derivation (DIMD) mode is enabled, the first syntax element being signaled on a sequence parameter set (SPS) raw byte sequence payload (RBSP) syntax;
when the DIMD mode is enabled,
when a color component of a current block is a luma component and an inter prediction is not applied to the current block, obtaining a second syntax element indicating whether the DIMD mode is applied to the current block; and
when the DIMD mode is applied to the current block, reconstructing the current block based on the DIMD mode,
obtaining the bitstream including at least one of the first syntax element or the second syntax element.
14 . The method of claim 13 , wherein the reconstructing of the current block based on the DIMD mode comprises:
obtaining directional information of neighboring blocks of the current block;
selecting, from the directional information, first directional information which most frequently occurs and second directional information which second most frequently occurs; and
reconstructing the current block based on the first directional information and the second directional information.
15 . The method of claim 14 , wherein the current block is reconstructed based on a weight value corresponding to the first directional information and a weight value corresponding to the second directional information.
16 . The method of claim 14 , wherein the current block is reconstructed using a first prediction mode and a derived intra-prediction mode generated based on the first directional information and the second directional information, and
the first prediction mode is a planar mode.
17 . A video signal processing method comprising:
parsing a first syntax element indicating whether a decoder side intra mode derivation (DIMD) mode is enabled, the first syntax element being signaled on a sequence parameter set (SPS) raw byte sequence payload (RBSP) syntax;
when the first syntax element indicates the DIMD mode is enabled,
when a color component of a current block is a luma component and an inter prediction is not applied to the current block, parsing a second syntax element indicating whether the DIMD mode is applied to the current block; and
when the second syntax element indicates the DIMD mode is applied to the current block, reconstructing the current block based on the DIMD mode.