1. An image processing apparatus comprising: a dividing unit configured to divide a frame of a moving image into a changing area in which there is an active object and a changeless area in which there is a stationary object; and a generation unit configured to generate a still image by compositing an area corresponding to the changeless area in each of X frame(s) (where X is an integer of 1 or more) among a plurality of frames included in the moving image and an area corresponding to the changing area in each of Y frames (where Y is an integer greater than X) among the plurality of frames.