Quote:"With the crop tool, crop the image to the smallest rectangle that still contains the whole painting (this can leave some bits of the frame)."
I believe that this point should be better observed.
After the handles are dragged to the corners of the image, they will be aligned to the initial rectangle defined by the crop tool.
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Samj Portable - Gimp 2.10.28 - Win-10 /64.
Samj Portable - Gimp 2.10.28 - Win-10 /64.