I have not mentioned scaling.
If I just crop, the shifted layer will be off by one pixel in the x and y directions. Therefore, there will be a difference at each pixel where there was none before. I am becoming convinced that my method is not understood, sorry.
[edit] here is an image cropped by one pixel on two sides and moved by one pixel in the x and y directions then compared by ‘Difference’:
Completely as I predicted. We must be talking at cross-purposes!
As we continue to discuss how to compare different JPEG methods with the original TIFF, the value of my contribution drops rapidly toward zero.
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