Image viewer zoom pixel accuracy

Help & Support
1

Both in the image viewer and the image viewer pane, some artifacts appear in the image when zooming in.
For instance, when I open the ‘test.bmp’ image containing white and black pixels only test, it is scaled using nearest-neighbor method which does not intend blurring. However, some pixels appear gray / blurred in the viewer:

viewer_bmp_nearest
viewer_bmp_nearest472×507 6.78 KB

When I convert the file to png, bicubic scaling is applied when zooming instead of nearest-neighbor. It looks OK except it is shifted by half a pixel down and to the left (note the left pixel column and the bottom pixel row which are cropped while the right pixel column and the top pixel row are extended) :

viewer_png_bicubic
viewer_png_bicubic472×507 9.86 KB

Is it possible to fix the viewer zooming algorithms?

Directory Opus Pro 12.23 Build 7655 x64
OS 10.0 (B:19042 P:2 T:1) SP 0.0

test_files.zip (22.3 KB)

2

It's not Opus doing that but Windows. We just ask Windows to scale the image, with a preferred scaling mode which it sometimes overrides due to a heuristic that it applies.

It would take a re-rewrite of the viewer to make it use different rendering APIs to change this. That's something we're thinking of doing in the long term, but won't happen any time soon (and we keep pushing it back due to other work).

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