An image processing system and method for comparing and correcting two monochromic images A2 and B2 that extracts a skeleton of objects in the monochromic image A2 to generate a skeleton image A3 and extracts a skeleton of objects in the monochromic image B2 to generate a skeleton image B3. The system and method then covers the skeleton image A3 with the monochromic image B2 to generate a covered image A4, and covers the skeleton image B3 with the monochromic image A2 to generate a covered image B4. The system and method further corrects allowable variances in the covered images A4 and B4, and outputs the covered images whose variances have been corrected.