1. An image processing apparatus comprising: a block division unit configured to perform a block division process on a first image selected from the first image and a second image, the first image and the second image being images photographed from different points of view; a similarity calculation unit configured to calculate similarities between blocks in the first image that are defined by the block division unit and image regions that form the second image; a likelihood calculation unit configured to calculate likelihoods of each candidate corresponding image region in the second image with respect to individual sets of adjacent blocks in the first image, the calculation being based on a positional relationship of the candidate corresponding image region; and a corresponding position determination unit configured to determine evaluation values of each candidate corresponding image region in the second image with respect to the blocks in the first image using similarities calculated by the similarity calculation unit and likelihoods calculated by the likelihood calculation unit and to determine image regions in the second image that correspond to the blocks in the first image by comparing the determined evaluation values.