An image processing system comprises a printer and a reader which are mechanically and functionally separated in such a manner that they can be used independently of each other and the transmission of image information is possible therebetween. Said reader includes an operating unit which cooperates with the printer to perform many functions such as the image operating function, the image transfer function, the presetting function and the image quality processing function, in addition to a function of a conventional copier. Said operating unit consists of a general purpose key portion; a soft key portion which is used for optionally creating the copy transfer functions and having function keys and displays corresponding to said keys, said displays being adapted to display key labels and messages to a user in cooperation with a driver, CPU and controller; and a function key preset key portion which is used for registering, reading and resetting the image transfer functions and having a standard mode return key, preset keys and preset key displays corresponding to said reset keys and adapted to display the reset position.