1. An image processing method used in an image processing apparatus which has a display for displaying an image and modifies a photographed image, the image processing method comprising: creating a three-dimensional proto-model of a subject; creating a three-dimensional model of the subject by projecting the subject portion of a photographed image on the surface of the three-dimensional proto-model and mapping the subject image onto the surface of the three-dimensional proto-model; displaying the three-dimensional model of the subject obtained by mapping on the display; transforming or modifying the shape of the three-dimensional model of the subject displayed on the display; creating a two-dimensional modified subject image by projecting the image of the transformed or modified three-dimensional model of the subject in the direction opposite to the direction in which the photographed image is projected; combining the two-dimensional modified subject image obtained by projecting the image in the opposite direction with the photographed image; and displaying the combined image as the modified photographed image on the display.