An image processing system includes a first image forming apparatus to perform an image generation operation, a second image forming apparatus to perform an image generation operation, and a processing control apparatus to control the first image forming apparatus and the second image forming apparatus to output an output target image by using the first image forming apparatus and the second image forming apparatus based on an output command information of the output target image, the output command information including first information related to the image generation operation of the output target image, second information related to collation assigned to the output target image, and third information related to one or more graphic marks providable to the output target image based on the second information related to the collation.