Image input method, image input apparatus, and recording medium

When compositing a plurality of acquired partial images, the effects of differences in viewpoint contained in the partial images can be reduced, and a high quality wide-viewfield image is inputted. An image input apparatus for photographing parts of a field to be photographed while altering the photographic direction by rotating a camera, projecting a plurality of partial images of the field to be photographed which are obtained onto a projection surface, and based on the results of this projection, conducting compositing on a composite image surface, and inputting the composite image, wherein is provided an image compositing mechanism 009, which employs the rotational center of the camera as the center of projection during the compositing of the plurality of partial images, and which employs, as the projection point of a pixel of a partial image, the intersection point between the projection surface which is established in space and a straight line, which is parallel to a straight line connecting the viewpoint of the camera and the pixel in the partial image in an image plane formed by the plurality of partial images, and which passes through the rotational center of the camera.