1. An image processing apparatus comprising: a unit which acquires a physical space image; an extraction unit which extracts a first region including pixels having a predetermined pixel value in the physical space image; a calculation unit which calculates a motion vector of an object in the physical space image; a specifying unit which specifies, using the motion vector, a second region that moves together with the first region; a generation unit which generates a virtual space image; and a superimposition unit which superimposes the virtual space image on a region different from the first region and the second region in the physical space image.