1. A method for acquiring a projection image of an actual movement trajectory of a subject, comprising: photographing a moving subject by means of a fixed camera; and converting the coordinates on a camera image frame of the photographed images of the subject into the coordinates on an actual background region of the images, wherein as specific patterns of the actual background region are photographed by the fixed camera in advance, the coordinates on the actual background region of the specific patterns are acquired, and wherein the conversion is performed on the basis of information on mapping between the coordinates on the actual background region of the specific patterns and the coordinates on the camera image frame of the photographed images thereof.