TILE-BASED IMAGE DATA DECODING METHOD AND APPARATUS

Disclosed are a method and apparatus for decoding encoded image data that has been obtained by dividing image data into a plurality of tiles and encoding the image data on a tile-by-tile basis. JPEG encoding tables that were used in the encoding of each of the plurality of tiles are determined based upon the headers, the JPEG-encoded data of respective ones of the plurality of tiles is arranged based upon the sameness of the JPEG encoding tables, and RST marker codes are inserted between the items of JPEG-encoded data of respective tiles, thereby creating a string of encoded data. By successively decoding this created string of encoded data from the beginning thereof, JPEG decoding need not be initiated afresh for each and every tile of encoded data, thereby making high-speed decoding possible.