To efficiently operate the page displacing work of an image by storing an image processing parameter for each page of an original with plural pages, storing image processed image data for each page based on the image processing parameter, and changing the image processing parameter for each page as necessary.

An image processing parameter managing part 111 manages image processing parameters for input and output necessary for each image processing in an input image processing part 103 and an output image processing part 105 for each page. An image processing parameter management table set in the image processing parameter managing part 111 is composed of the set value of the image processing parameter for each page such as the balance value of each page of plural input images and present image concentration, saturation, and each Y, M, and C color corresponding to each page. In this case, the image processing parameter management table is respectively provided for input and output. The set value of the image processing parameter is managed for each page of the input image so that the image processing parameter can be changed for each page.