We are dealing with repeated photos. They are not orthophotos, just simple pics taken with common cameras from the ground. We compare photos taken at the begginging of the 20st century, or evven sometimes taken in 1990.
Until now we have been doing some research from a qualitative point of view, but we wonder how to add some quantitative analysis to our work.
Any suggestions (software, papers...) will be more than wellcome!