An image processing program causing a computer to execute image processing is provided. The image processing program causing the computer to execute: an image acquisition step (S1) of acquiring a frame image from a moving image; a person detection step (S8) of detecting a person from the frame image acquired in the image acquisition step; an orientation detection step (S10) of detecting an orientation of the person detected in the person detection step; a region setting step (S102, S103) of setting a person region including the person detected in the person detection step in the frame image acquired in the image acquisition step; a region expansion step (S108, S112) of expanding the person region set in the region setting step in the orientation of the person detected in the orientation detection step; and an output step (S15) of outputting the person region expanded in the region expansion step.