In the process of a registration between first and second images captured by different image pickup apparatuses, even if corresponding parts have different pixel values, different shapes and different field of view, the registration can be carried out with high speed and high degree of precision. In order to perform the registration between the first and second images, either of the first and second images is divided into segmented regions, and given physical property values are set to the segmented regions. Further, an image (pseudo image) having similar pixel values, shapes and field of view to the other image is created, and the pseudo image and the second image that have the same features are positioned, thereby performing the registration between the first and second images.