In order to allow an arbitrary combination of image processing function blocks and an arbitrary processing order to be executed with a single command and avoid calculation loads on a host CPU even when image processes in varying output image sizes are combined, the image signal processing apparatus of the present invention includes an individual processing sub program that operates image processes in page units or with an arbitrarily specified number of lines for each image processing function block and an individual processing parameter table that determines the individual processing contents and also provides a composite processing parameter table including image processing order information and image size related information and when an individual image processing command is issued, the image signal processing apparatus sets an individual processing parameter table in an image processing function block and executes the individual processing sub program.