An image processing apparatus which processes input image signals in real time. A plurality of image signals are input via input terminals. An external storage device stores a plurality of kinds of procedures for processing to be performed on image signals. A JOG dial specifies at least two kinds of procedures among the stored plurality of kinds of procedures, and enables the specified procedures and a procedure between the specified procedures to be arbitrarily changed and specified. When the procedure between the specified procedures is specified using the JOG dial, a CPU generates the specified procedure by interpolating the specified procedures, and carries out real-time processing on image signals for corresponding channels among the image signals for the plurality of channels according to the generated specified procedure.