This invention can generate a high-resolution, low-noise tomogram while minimizing the influences of the flicks of the eyeballs, the movement of the head, and the like. The invention is an image processing apparatus which processes a tomogram of an eye to be examined and includes detection units to detect the motion amount of the eye by using a signal obtained by capturing the tomogram, and a decision unit to decide the number of scanning lines for capturing of the tomogram based on the motion amount detected by the detection units.