Image coding apparatus, image coding method, image decoding apparatus, image decoding method, and storage medium

An image decoding method for decoding a plurality of encoded image frames in an encoded stream, each of the image frames being divided into a plurality of tiles, the plurality of image frames being encoded tile by tile, the image decoding method comprising:

• acquiring, from a parameter set in the encoded stream for the plurality of encoded image frames, division information including a number of columns of tiles and a number of rows of tiles in the plurality of encoded image frames, and uniform spacing information indicating whether the tiles have the same size;
• acquiring, from supplemental enhancement information (SEI) in the encoded stream for the plurality of encoded image frames, information indicating that a predetermined tile set including at least one tile is intended for a display, and position information of a predetermined tile set for a display of a corresponding image portion in each of the plurality of image frames, the position information of the predetermined tile set including a first tile position of a first tile including top-left corner of the predetermined tile set and a second tile position of a second tile including a bottom-right corner of the predetermined tile set;
• and
• decoding encoded image frames in the encoded stream using the division information including a number of columns of tiles and a number of rows of tiles and the uniform spacing information,
• wherein, when the image portion in the predetermined tile set corresponding to the position information acquired from the supplemental enhancement information (SEI) is reproduced for a display in accordance with the information indicating that a predetermined tile set including at least one tile is intended for a display, the predetermined tile set corresponding to the position information acquired from the supplemental enhancement information (SEI) is decoded with motion compensation by referring to a tile in a reference image frame at a corresponding position of the tile in the predetermined tile set without referring to any tiles in the reference image frame at positions different from the corresponding position of the predetermined tile set.