1. An image display apparatus of image processing and displaying a shot image of the ground surface having been taken with photographic equipment that is mounted on an airframe in the air, the image display apparatus comprising: an image frame computing means in which a shooting position in the air is specified three-dimensionally based on posture of said airframe and said photographic equipment with respect to said ground surface and a photographic area on the ground surface having been shot is obtained by computation; an image transformation means in which a shot image is transformed in conformity with said photographic area; a superposing means in which said transformed image is superposed on a map of a geographic information system; and a monitor display means for displaying said superposed map, wherein landmarks are extracted from said map of said geographic information system and said shot image respectively, and the corresponding landmarks are compared, whereby a parameter for use in computing a photographic area of the ground surface having been shot is compensated, and a shot image is displayed being superposed with high precision on said map of the geographic information system.