IMAGE DECODER DECODING IMAGE TO ALLOW FRAME AREA OF SHARING MUCH AREA IN STORAGE DEVICE TO BE USED FOR OTHER PURPOSE AND COMPUTER READABLE RECORDING MEDIUM RECORDING IMAGE DECODING PROGRAM

摘要

PROBLEM TO BE SOLVED: To obtain an image decoder where work areas to store various data such as OSD data are reserved in a memory without sacrificing image quality. SOLUTION: When a data reduction control section 64 receives a request to reserve storage areas for OSD data, the control section 64 aborts macro blocks equivalent to prescribed addresses of a display image. An OSD data access section 63 writes the OSD data to areas of a frame storage device where the aborted macro blocks have been stored. Since the areas equivalent to prescribed addresses of the display image in the frame storage device are assigned to the OSD data storage area only when reservation of the storage areas for the OSD data is requested, no image quality is deteriorated.