Method for encoding/decoding image signal, and device for the same

1. A method of decoding a video, the method comprising:

partitioning a current picture into a plurality of tiles;

decoding partitioning information representing whether a rectangular slice type is applied or not;

decoding slice number information indicating a number of slices; and

decoding tile index difference value information specifying a difference between an index of a top-left tile of a first slice and an index of a top-left tile of a second slice,

wherein the tile index difference value information is decoded from a bitstream only when a tile index difference value present flag, decoded from the bitstream, indicates that the tile index difference value information could be present in the bitstream,

wherein the index of the top-left tile of the second slice is determined by adding the difference specified by the tile index difference value information to the index of the top-left tile of the first slice, and

wherein whether to decode width information for the second slice from the bitstream or not is determined based on whether the top-left tile of the second slice is included in a rightmost tile column in the current picture.

2. The method of claim 1 , wherein the width information indicates a value subtracting 1 from a number of tile columns included in the second slice, and wherein when the top-left tile of the second slice is included in the rightmost tile column in the current picture, decoding the width information for the second slice is omitted and a value of the width information is inferred to 0.

3. The method of claim 2 , wherein whether the top-left tile of the second slice is included in the rightmost tile column is determined based on a modular operation between the index of the top-left tile of the second slice and a number of tile columns in the current picture.

4. The method of claim 1 , wherein whether to decode height information for the second slice from the bitstream or not is determined based on whether the top-left tile of the second slice is included in a lowest tile row in the current picture.

5. The method of claim 4 , wherein the height information indicates a value subtracting 1 from a number of tile rows included in the second slice, and wherein when the top-left tile of the second slice is included in the lowest tile row in the current picture, decoding the height information for the second slice is omitted and a value of the height information is inferred to 0.

6. The method of claim 5 , wherein whether the top-left tile of the second slice is included in the lowest tile row is determined based on a division operation between the index of the top-left tile of the second slice and a number of tile columns in the current picture.

7. The method of claim 1 ,

wherein whether to decode the tile index difference value present flag from the bitstream or not is determined based on the number of slices included in the current picture.

8. A method of encoding a video, the method comprising:

partitioning a current picture into a plurality of tiles;

determining whether a rectangular slice type is applied or not;

encoding slice number information indicating a number of slices; and

encoding tile index difference value information specifying a difference between an index of a top-left tile of a first slice and an index of a top-left tile of a second slice,

wherein a tile index difference value present flag, indicating whether the tile index difference value information is present in a bitstream or not, is further encoded in the bitstream,

wherein the tile index difference value information has a value derived by subtracting the index of the top-left tile of the second slice from the index of the top-left tile of the first slice, and

wherein whether to encode width information for the second slice into the bitstream or not is determined based on whether the top-left tile of the second slice is included in a rightmost tile column in the current picture.

9. The method of claim 8 , wherein the width information indicates a value subtracting 1 from a number of tile columns included in the second slice, and

wherein when the top-left tile of the second slice is included in the rightmost tile column in the current picture, encoding the width information for the second slice is omitted.

10. The method of claim 8 , wherein whether to encode height information for the second slice into the bitstream or not is determined based on whether the top-left tile of the second slice is included in a lowest tile row in the current picture.

11. The method of claim 10 , wherein the height information indicates a value subtracting 1 from a number of tile rows included in the second slice, and

wherein when the top-left tile of the second slice is included in the lowest tile row in the current picture, encoding the height information for the second slice is omitted.

12. A non-transitory computer-readable medium for storing data associated with a video, comprising:

a data stream stored in the non-transitory computer-readable medium, the data stream comprising:

partitioning information representing whether a rectangular slice type is applied or not,

slice number information indicating a number of slices,

tile index delta present flag indicating whether tile index value information is present or not, and

the tile index difference value information specifying a difference between an index of a top-left tile of a first slice and an index of a top-left tile of a second slice,

wherein the index of the top-left tile of the second slice is determined by adding the difference specified by the tile index difference value information to the index of the top-left tile of the first slice, and

wherein whether the compressed video data further comprises width information for the second slice or not is determined based on whether the top-left tile of the second slice is included in a rightmost tile column in the current picture.