In an image processing apparatus, a detection unit detects a moving object from a captured image captured by an image capturing unit. An extraction unit extracts an edge from the captured image. A determination unit determines, based on a position of the moving object included in the captured image, whether to superimpose the edge on a region corresponding to the moving object in a background image. A generation unit generates an output image by superimposing a mask image, for obscuring the moving object, on the region in the background image and superimposing the edge, determined by the determination unit to be superimposed, on the region in the background image.