Method, apparatus, and recording medium for encoding/decoding image
Disclosed herein are a method, apparatus, and storage medium for image encoding/decoding. In the image decoding method, whether filtering is to be performed across a boundary of a target block is determined, and filtering strength for the boundary of the target block and the number of samples to be used for filtering are determined. Based on this determination, filtering across the boundary of the target block is performed. When the filtering strength and the number of samples are determined, coding parameters related to the target block and a neighbor block, such as a block size and a prediction mode, are used.
1 . A video decoding method, comprising:
determining whether to perform filtering on a target boundary; and
performing the filtering on the target boundary in a case that it is determined to perform the filtering, wherein:
whether to perform the filtering on the target boundary is determined based on whether the target boundary corresponds to 4×4 pixel grid boundaries of a target picture in a case that the target boundary is a luma component boundary, and
the filtering on the target boundary is not performed in a case that the target boundary does not correspond to the 4×4 pixel grid boundaries of the target picture in the case that the target boundary is the luma component boundary.
2 . The video decoding method of claim 1 , wherein:
the target boundary is a boundary for a specific unit; and
whether to perform filtering on the boundary for the specific unit is determined based on information for the specific unit.
3 . The video decoding method of claim 2 , wherein:
the specific unit is a tile.
4 . The video decoding method of claim 3 , wherein:
the information is signaled in a picture parameter set.
5 . A video encoding method, comprising:
determining whether to perform filtering on a target boundary; and
performing the filtering on the target boundary in a case that it is determined to perform the filtering, wherein:
whether to perform the filtering on the target boundary is determined based on whether the target boundary corresponds to 4×4 pixel grid boundaries of a target picture in a case that the target boundary is a luma component boundary, and
the filtering on the target boundary is not performed in a case that the target boundary does not correspond to the 4×4 pixel grid boundaries of the target picture in the case that the target boundary is the luma component boundary.
6 . The video decoding method of claim 1 , wherein:
the filtering is a deblocking filtering,
whether to perform the deblocking filtering on the target boundary is determined based on whether the target boundary corresponds to predetermined-sized pixel grid boundaries of the target picture, and
a size of the predetermined-sized pixel grid boundaries is determined based whether the target boundary is the luma component boundary or a chroma component boundary.
7 . The video decoding method of claim 1 , wherein:
the filtering on the target boundary is not performed in a case that the target boundary does not correspond to 8×8 pixel grid boundaries of the target picture in a case that the target boundary is a chroma component boundary.
8 . The video decoding method of claim 1 , wherein:
a flag indicating whether deblocking filtering is performed on a tile boundary is obtained from a bitstream, and
the filtering is not performed on the target boundary in a case that the target boundary is a boundary between tiles and the flag indicates the deblocking filtering is not performed on the tile boundary.
9 . The video decoding method of claim 1 , wherein:
a flag indicating whether deblocking filtering is performed on a slice comprising the target boundary is obtained from a bitstream, and
the filtering is not performed on the target boundary in a case that the flag indicates the deblocking filtering is not performed on the slice.
10 . A non-transitory computer-readable recording medium storing configured to store and transmit a bitstream generated by a computer program, wherein, the computer program, when executed by a processor, causes a video encoding apparatus to perform following steps to generate the bitstream:
determining whether to perform filtering on a target boundary;
performing the filtering on the target boundary in a case that it is determined to perform the filtering;
generating the bitstream comprising filter information indicating whether the filtering is performed on the target boundary; and
storing the bitstream in the non-transitory computer-readable recording medium, wherein
whether to perform the filtering on the target boundary is determined based on whether the target boundary corresponds to 4×4 pixel grid boundaries of a target picture in a case that the target boundary is a luma component boundary, and
the filtering on the target boundary is not performed in a case that the target boundary does not correspond to the 4×4 pixel grid boundaries of the target picture in the case that the target boundary is the luma component boundary.
11 . The non-transitory computer-readable recording medium of claim 10 , wherein:
the target boundary is a boundary for a tile, and
whether to perform the filtering on the boundary for the tile is determined based on information for the tile.
12 . The non-transitory computer-readable recording medium of claim 10 , wherein:
the filtering is a deblocking filtering,
whether to perform the deblocking filtering on the target boundary is determined based on whether the target boundary corresponds to predetermined-sized pixel grid boundaries of the target picture, and
a size of the predetermined-sized pixel grid boundaries is determined based whether the target boundary is the luma component boundary or a chroma component boundary.
13 . A non-transitory computer-readable recording medium storing program instructions for transmitting a bitstream, the program instructions comprising:
an instruction to perform generating the bitstream; and
an instruction to transmit the bitstream,
wherein the generating the bitstream comprises:
generating the bitstream comprising filter information generated by a video encoding method,
wherein the video encoding method comprises:
determining whether to perform filtering on a target boundary;
performing the filtering on the target boundary in a case that it is determined to perform the filtering; and
generating the filter information used to determine whether the filtering is performed on the target boundary,
wherein whether to perform the filtering on the target boundary is determined based on whether the target boundary corresponds to 4×4 pixel grid boundaries of a target picture in a case that the target boundary is a luma component boundary, and
wherein the filtering on the target boundary is not performed in a case that the target boundary does not correspond to the 4×4 pixel grid boundaries of the target picture in a case that the target boundary is the luma component boundary.
14 . The non-transitory computer-readable recording medium of claim 13 , wherein:
the target boundary is a boundary for a tile, and
whether to perform the filtering on the boundary for the tile is determined based on information for the tile.
15 . The non-transitory computer-readable recording medium of claim 13 , wherein:
the filtering is a deblocking filtering,
whether to perform the deblocking filtering on the target boundary is determined based on whether the target boundary corresponds to predetermined-sized pixel grid boundaries of the target picture, and
a size of the predetermined-sized pixel grid boundaries is determined based whether the target boundary is the luma component boundary or a chroma component boundary.
16 . The video encoding method of claim 5 , wherein:
the target boundary is a boundary for a tile, and
whether to perform the filtering on the boundary for the tile is determined based on information for the tile.
17 . The video encoding method of claim 5 , wherein:
the filtering is a deblocking filtering,
whether to perform the deblocking filtering on the target boundary is determined based on whether the target boundary corresponds to predetermined-sized pixel grid boundaries of the target picture, and
a size of the predetermined-sized pixel grid boundaries is determined based whether the target boundary is the luma component boundary or a chroma component boundary.