use GIMP to load the edited images and analyze them.
Learn Technical Photography for Art Examination
Technical Photography is one of the most powerful—and often overlooked—tools for the scientific examination of art and archaeology. If you are a conservator, scientist, or art collector and you are not yet familiar with this method, it is truly a missed opportunity. Using simple, affordable equipment and a clear methodology, Technical Photography allows you to reveal underdrawings, retouchings, material differences, and conservation issues in a completely non-invasive way. Far from being complex or inaccessible, it is an easy entry point into scientific analysis. In many cases, Technical Photography represents the first essential step toward a deeper understanding of artworks and archaeological objects.