Method for encoding/decoding image signal and device therefor
An image decoding method according to the present disclosure comprises the steps of: determining whether a picture is to be divided into multiple sub-pictures; when it is determined that the picture is to be divided into multiple sub-pictures, dividing the picture into multiple sub-pictures; and determining whether the multiple sub-pictures are independent of each other.
1. A video decoding method comprising:
determining whether a picture is encoded according to a plurality of sub-pictures;
partitioning the picture into the plurality of sub-pictures when it is determined that the picture is encoded according to the plurality of sub-pictures; and
determining whether the plurality of sub-pictures have independence,
wherein the determination on whether to have independence is based on a first flag representing whether all of the plurality of sub-pictures have independence,
wherein a first value for the first flag indicates that all of the plurality of sub-pictures have independence, and
wherein a second value for the first flag indicates that at least one of the plurality of sub-pictures does not have independence.
2. The method of claim 1 , wherein when the first flag represents that at least one of the plurality of sub-pictures does not have independence, a second flag representing whether each sub-picture has independence is parsed for each of the plurality of subpictures.
3. The method of claim 1 , wherein partitioning the picture includes determining a number of the sub-pictures included by the picture and determining position information and size information of each of the sub-pictures.
4. The method of claim 3 , wherein signaling of the position information is omitted for a first one among the sub-pictures.
5. The method of claim 3 , wherein signaling of the size information is omitted for a last one among the sub-pictures.
6. The method of claim 3 , wherein the size information includes width information representing a number of coding tree units for a horizontal direction in the sub-picture and height information representing the number of coding tree units for a vertical direction in the sub-picture.
7. A video encoding method comprising:
determining whether a picture is to be encoded according to a plurality of sub-pictures;
partitioning the picture into the plurality of sub-pictures when it is determined that the picture is to be encoded according to the plurality of sub-pictures; and
determining whether the plurality of sub-pictures have independence,
wherein a first flag representing whether all of the plurality of sub-pictures have independence is encoded in a bitstream,
wherein a first value for the first flag indicates that all of the plurality of sub-pictures have independence, and
wherein a second value for the first flag indicates that at least one of the plurality of sub-pictures does not have independence.
8. The method of claim 7 , wherein when the first flag represents that at least one of the plurality of sub-pictures does not have independence, a second flag representing whether each sub-picture has independence is encoded for each of the plurality of subpictures.
9. The method of claim 7 , wherein the method further includes encoding partitioning information of the picture, and
wherein the partitioning information includes position information and size information of each of the sub-pictures.
10. The method of claim 9 , wherein encoding of the position information is omitted for a first one among the sub-pictures.
11. The method of claim 9 , wherein encoding of the size information is omitted for a last one among the sub-pictures.
12. The method of claim 9 , wherein the size information includes width information representing a number of coding tree units for a horizontal direction in the sub-picture and height information representing the number of coding tree units for a vertical direction in the sub-picture.