Encoded data is decoded based on tile data division information, tile data position information, block line data division information, and block line data position information. The tile data division information indicates whether the encoded data is composed of tile data items that serve as encoded data items of tiles. The tile data position information indicates positions of the tile data items. The block line data division information indicates whether each tile data item is composed of first block line data and second block line data. The first block line data serves as encoded data of a first block line that is a set of blocks arranged linearly. The second block line data serves as encoded data of a second block line next to the first block line. The block line data position information indicates a position of the second block line data.