To provide an image processor for processing image data every unit of tile images which suppresses the required buffer size for generating output tiles and reduces the complexity of a process sequence.

In an image processor block (2149), image data are dealt with by tile unit in the form of packets and the data packet involves at least information about the scale varying process. Upon receipt of a data packet, a resolution changer (2116) for the scale varying process applies the scale varying process to tile image data involved in the data packet, based on the information about scale varying process involved in the data packet, and generates and outputs effective pixel range information indicating the range within which image data resulting from the scale varying process exist in the tile and a new data packet involving image data resulting from the scale varying process.