Zoom works incorrectly on scaled high-resolution displays

[andrejpodzimek]

With a 200% scaling (e.g. on a 218 ppi 5k monitor), choosing a 100% zoom seems to yield (in fact) a 200% zoom, i.e. “4 monitor pixels per image pixel” instead of “pixel to pixel”.

This↑ approach is usually taken by web browsers when no high-resolution versions of images are available; browsers scale (and therefore blur, to an extent) images to prevent them from looking tiny and odd around (scaled) web page text. However, programs that work with images without adjacent (scaled) text should probably keep the original notion of pixels, regardless font and UI scaling.

An example troublesome use case: I take a screenshot (with UI set to a 200% scaling), open it in the Annotator and choose a 100% zoom. The Annotator shows a blurred 200%-like zoom of the screenshot. Setting 50% seems to be just right for a “1:1 appearance”.

[andrejpodzimek]

A few more experiments suggest that this problem may be affecting only screenshots pasted from the clipboard, but not images imported from a file.

[phase1geo]

I believe that I am able to reproduce this issue with Annotator 2.0. I will look into fixing this issue.