An image processing apparatus comprising: an image obtaining unit obtaining a first image and a second image different from the first image; a deformation information obtaining unit obtaining deformation information representing deformation between the first image and the second image; a deformed image generating unit generating a first deformed image of the first image deformed in accordance with the second image and a second deformed image of the second image deformed in accordance with the first image; and a display controlling unit displaying the first image, the second image, an image based on the first deformed image, and an image based on the second deformed image is used.