Image encoding/decoding method and device

1. A video encoding method, the method comprising:

partitioning a current picture into a plurality of tiles; and

partitioning a current tile among the plurality of tiles into a plurality of slices,

wherein slice number information indicating a number of slices for which height information is explicitly encoded is encoded into a bitstream,

wherein, for a first slice of which an order is less than or equal to the number of slices, the height information is explicitly encoded,

wherein, for a second slice of which an order is greater than the number of slices, encoding the height information is skipped, and

wherein a height of the second slice is the same as a height of a previous slice for which the height information is encoded lastly.

2. The video encoding method of claim 1 ,

wherein the height information represents a height of a slice in a unit of CTU (Coding Tree Unit) or CTB (Coding Tree Block).

3. The video encoding method of claim 1 , wherein the method further comprises:

encoding rectangular slice information indicating whether a rectangular slice mode is applied to determine slices,

wherein in response to the rectangular slice mode being applied, slice-tile width information and slice-tile height information are explicitly encoded for a slice,

wherein the slice-tile width information represents a value subtracting 1 from a width of the slice represented in a unit of tile columns, and

wherein the slice-tile height information represents a value subtracting 1 from a height of the slice represented in a unit of tile rows.

4. The video encoding method of claim 1 ,

wherein the slice number information is encoded into the bitstream when both the slice-tile width information and the slice-tile height information are encoded as 0.

5. The video encoding method of claim 4 , wherein when the slice is composed of a plurality of tiles, at least one of the slice-tile width information or the slice-tile height information is encoded with a value greater than 0, and

wherein when the slice has a equal to or smaller size that the current slice, both the slice-tile width information and the slice-tile height information are encoded with a value 0 .

6. The video encoding method of claim 1 , further comprising:

encoding single tile information indicating whether or not a plurality of tiles are comprised in the current picture; and

in response to the single tile information indicating that the current picture is not composed of a single tile, encoding tile height information indicating a height of a tile row and tile width information indicating a width of a tile column.

7. The video encoding method of claim 6 ,

wherein the tile width information is not encoded for a last tile column which is adjacent to a right boundary of the current picture, and a width of the last tile column is the same as a value subtracting a sum of widths of previous tile columns from a width of the current picture.

8. The video encoding method of claim 1 ,

wherein the height of the second slice is the same as a smaller one among the height of the previous slice and a remaining height of the current tile, the remaining height representing a value subtracting a sum of heights of previous slices from a height of the current tile.

9. A video decoding method, the method comprising:

partitioning a current picture into a plurality of tiles; and

partitioning a current tile among the plurality of tiles into a plurality of slices,

wherein the current tile is partitioned into the plurality of slices based on slice number information indicating a number of slices for which height information is explicitly signaled,

wherein a height of a first slice of which an order is less than or equal to the number of slices is determined based on the height information explicitly decoded from a bitstream,

wherein a height of a second slice of which an order is greater than the number of slices is determined based on a height of a previous slice for which the height information is decoded lastly.

10. The video decoding method of claim 9 ,

wherein the height information represents a height of a slice in a unit of CTU (Coding Tree Unit) or CTB (Coding Tree Block).

11. The video decoding method of claim 9 ,

wherein in response to the second slice being a last slice among the plurality of slices, the height of the second slice is determined as the remaining height of the current tile.

12. The video decoding method of claim 9 , wherein the method further comprises decoding rectangular slice information indicating whether a rectangular slice mode is applied to determine slices,

wherein in response to the rectangular slice mode being applied, slice-tile width information and slice-tile height information are explicitly signaled for a slice,

wherein the slice-tile width information represents a value subtracting 1 from a width of the slice represented in a unit of tile columns, and

wherein the slice-tile height information represents a value subtracting 1 from a height of the slice represented in a unit of tile rows.

13. The video decoding method of claim 12 , wherein the slice number information is decoded from the bitstream when both the slice-tile width information and the slice-tile height information are 0.

14. The video decoding method of claim 13 , further comprising:

wherein when the slice-tile width information or the slice-tile height information is greater than 0, the slice is composed of a plurality of tiles, and

wherein when both the slice-tile width information and the slice-tile height information are 0, the slice is determined to have a equal to or smaller size than the current tile.

15. The video decoding method of claim 9 , further comprising:

decoding single tile information indicating whether or not a plurality of tiles are comprised in the current picture; and

in response to the single tile information indicating that the current picture is not composed of a single tile, decoding tile height information indicating a height of a tile row and tile width information indicating a width of a tile column.

16. The video decoding method of claim 15 ,

wherein the tile width information is not decoded for a last tile column which is adjacent to a right boundary of the current picture, and a width of the last tile column is inferred by subtracting a sum of widths of previous tile columns from a width of the current picture.

17. The video decoding method of claim 9 ,

wherein the height of the second slice is determined as a smaller one among the height of the previous slice and a remaining height of the current tile, the remaining height representing a value subtracting a sum of heights of previous slices from a height of the current tile.

18. A computer-readable recording medium for storing a bitstream comprising video encoding data which is generated by a video encoding method,

wherein the video encoding method comprises:

partitioning a current picture into a plurality of tiles; and

partitioning a current tile among the plurality of tiles into a plurality of slices,

wherein slice number information indicating a number of slices for which height information is explicitly encoded is encoded into a bitstream,

wherein, for a first slice of which an order is less than or equal to the number of slices, the height information is explicitly encoded,

wherein, for a second slice of which an order is greater than the number of slices, encoding the height information is skipped, and

wherein a height of the second slice is the same as a height of a previous slice for which the height information is encoded lastly.