Image processing device which can perform a plurality of types of image processing at high speed

An image processing device which receives image data from an image reading device which divides each line of image data into ‘n’ blocks of image data, said ‘n’ being an arbitrary number, and transfers the ‘n’ blocks of image data in synchronization with respective synchronization signals, said image processing device comprising:

• an image processing portion which performs predetermined image processing on the image data received from said image reading device, and comprises a first processing portion which, using respective synchronization signals for the ‘n’ blocks of image data, performs first predetermined image processing on the image data in parallel, and a second processing portion which combines the ‘n’ blocks of image data in line units, and performs second predetermined image processing on the thus-obtained image data in parallel using synchronization signals, the period of each of which is ‘n’ times the period of each of the respective synchronization signals used by said first image processing portion;
• and
• an image-combination processing portion which performs processing of combining image data produced by an image producing portion and the image data output from said image processing portion.