An image processing apparatus configured to calculate deformation between a first image and a second image includes a calculation order determination unit that determines calculation order of a plurality of partial regions into which the second image is divided, a calculation unit that calculates the deformation between the first image and the second image for each of the plurality of partial regions in the determined calculation order of the plurality of partial regions, a deformed image generation unit that generates a deformed image by deforming the first image based on the calculated deformation of the plurality of partial regions, and a display control unit that causes a display unit to display the generated deformed image.