an image forming system includes an image forming apparatus ; an image processor , the image processor includes instruction element for requesting image processing parameter adjustment data from the image forming apparatus ; a receiver for receiving image processing parameter adjustment data from the image forming apparatus , and image processor for performing adjustment of an image processing parameter based on the image processing parameter adjustment data received by the receiver . the image forming apparatus includes a data creating device for creating image processing parameter adjustment data , and a transmitter for transmitting the image processing parameter adjustment data created by the data creating element to the image processor .