1. An image processing apparatus comprising: a memory configured to store a plurality of combinations of display methods decided for each step of a workflow regarding whether an X-ray image serving as a first image is to be displayed as a moving image or a still image and a second image is to be displayed as a moving image or a still image; and processing circuitry configured to determine, according to a step of the workflow, a combination of display methods of the X-ray image and the second image from the plurality of combinations of display methods, and control a display to display a superimposed image in which the X-ray image and the second image displayed by the determined combination of display methods are superimposed.