1. An image processing apparatus that performs image processing for input image data to output an image, the apparatus comprising: a specific image information adding portion that adds specific image information to control unauthorized copying of the image, said specific image information representing a specific image to the image data when the image processing is performed for the image data; a specific image information setting portion that sets a color and number of the specific image information; and a plurality of image data input paths that input the image data subjected to the image processing, wherein the specific image information setting portion sets the color and number of the specific image information in advance for each of the plurality of the image data input paths.