An image processing system includes a plurality of memories for storing (1) a procedure control program and (2) a task program for automatic closed loop control. Each program is grouped into a plurality of groups of programs in response to one of a plurality of selectable stages corresponding to priority required to execute an image processing. Each group of programs is task scheduled and one of the stages is selected. The task schedule is controlled in response to the selected stage and the group of programs is supervised corresponding to the selected stage.