Building shape change detecting method, and building shape change detecting system

A building shape change detecting system, comprising:

• photographing means for photographing a ground surface image from an aircraft;
• observation feature point extracting means for extracting, on the aircraft, an observation feature point corresponding to a ground object from the photographed ground surface image;
• data transmitting means for transmitting data representative of the observation feature point from the aircraft to a ground station in a wireless manner;
• building projected image producing means for performing, at the ground station, a projection calculation based upon (i) building shape recording information which has previously been stored, and (ii) both a flying position and a flying attitude of the aircraft when the photographed ground surface image was photographed, and producing a building projected image as viewed from the flying position;
• and
• change detecting means for comparing, at the ground station, the observation feature point with the building projected image, and detecting a change in the building shape, wherein
• the observation feature point extracting means for extracting pixels as the observation feature points, which constitute an edge, from the photographed ground surface image corresponding to a digital image.