dpi value changed when changing the image size

Why is the dpi value changed when changing the image size?

Because you’re changing the size of the image (the area it takes), not the resolution of the image.

If you have a 800x600 image at 200DPI, that’s 4" by 3" of space. Change that to 8" by 6" without modifying the resolution, and that’s 100DPI.

If a png was created in, for example, print-600 dpi and was transferred to the text file, its resolution should not change, but should be retained for printing. This has nothing to do with the translation into monitor dpi. However, when resizing shows the translation on the screen, it’s just confusing and unnecessary.

Scrivener cannot add (or remove) information to an image file. If you make it bigger with the same number of pixels, the DPI goes down.

Resizing in the Editor affects the size of the image in the output document. It’s not “just” a display issue.