A disclosed image processing system includes an image forming apparatus and an image processing apparatus connected via a network, wherein the image forming apparatus includes a receiving portion receiving a designation of a workflow produced by arbitrarily assembling a plug-in of an image dividing and converting process for image data and a plug-in of an output process and includes an image dividing and converting process, and a communicating portion transmitting a request for processing the workflow to the image processing apparatus along with the image data, and the image processing apparatus includes a workflow controlling portion carrying out the processes when a request for carrying out these processes is received, and a workflow processing portion carrying out the workflow while dividing the image data by using a length of a longitudinal side of the image data based on a control with the workflow controlling portion.