What you are pointing out here is that simply showing differences in images doesn't prove forgery. Other things, such as normal image processing steps, can create differences. As I have said elsewhere, Polarik hasn't proven that any of the differences he finds (even when they really exist) are the result of forgery. He just says so.
mlo, I didn't word it that way. I intentionally said less than I could have. But I don't want people to think that your "summation" is my thinking.
The key to this problem (the COLB scan) is in the questions I asked at the end of posts 321 and post 328. If Polarik indeed knows what he is talking about, he should answer every single one of them.
Let's give him a couple of days to get his act together. If he can't state why he overlooked the most basic considerations with regard to image processing, then I think it is safe to discount any conclusions he made about the scan.
I have not even touched on his conclusions regarding the factcheck photos, but I can say with a high degree of certainty that he has not properly treated the projective geometry that would be needed to back up his conclusions, and that pretty much sinks a large portion of his report.
There may still be stuff in his report that is helpful, but he sure hasn't made it easy.
I have said "Polarik only has to be right once", and doesn't even have to be right for the right reasons. Maybe he would like to point out what his best arguments are?