... The good Messieurs JayUtah and Oystien have shown you precisely why.
Wowowoooowwww that's waaaaaay too much credit! I really am an absolute beginner with digital imaging and image editing/conversion, I only know a part of the most basic concepts.
Just enough to have a general feel to have an idea what the minimum requirements would be to prove that a certain analytical method validly, with good statistical power, actually distinguishes between "natural" image degradation and "artificial" manipulation of the sort our interlocutor suggests.
In other words: I expect some well-structured thinking to occur, where a comprehensive explanation if given.
But I noticed something just now that gives little reason to hope for such a comprehensive explanation to be forthcoming:
nt1's posts are organized as mostly single lines, separated by paragraph breaks (2 line breaks). Each such line (even if there are two or three on occasion, those hardly qualify as paragraphs) contains short sentences, or mere phrases that do not amount to a grammatically complete sentence. There is no coherent, structured argument. Ever. Just blurted out half-ideas. And I suggest this accurately reflects a lack of coherent and comprehensive thinking.
Contrast with any post by JayUtah (and many of mine): These contain actual paragraphs. Each paragraph composed of several full, grammital sentences, each devoted to developing an idea.
From paragraph to paragraph, the argument keeps evolving.
What a sharp contrast to nt1's blurted-out one-liners!