Corresponding points are searched based on an error between light beam
vectors projected on a projection plane without performing comparison
between pixel values at the corresponding points. The necessity for use
of cameras having a same camera lens or a same distortion parameter is
eliminated, and picked up images of different camera models can be
connected to each other. Since original picked up images are pasted
directly to an output frame based on errors between light beam vectors
without transforming any picked up image once into a pinhole image,
deterioration of pixels can be suppressed. Accordingly, picked up images
of various cameras which are different in terms of the lens distortion or
the camera model from each other can be suitably pasted together.