darktable 2.4 issue with Windows 10 high-dpi scaling


(Francis Shum) #1

Hi,

I am using darktable 2.4.3 in Windows 10. The scaling in Windows is set to 225% for my 4k display.

I have found these issues with the center preview image in Darkroom.

  1. The zoom% of the center image is wrongly set. It looks like to me that the actual zoom% is 225% of the chosen magnification. For example, when I choose 100% zoom, the center image is actually at 225%.
  2. The amount highlight details shown in the center image varies with the zoom%. But this issue is apparent only at areas with extreme local contrast.

I am not sure if this is a bug of the windows version of darktable or due to some abnormal settings in my windows 10. Please kindly advise.

I have prepared some screenshots of the affected area in the center image, under different Windows Scaling%, OpenCL, Zoom%. I have also prepared a 100% screenshot from the actually exported image for reference. All images are cropped to show only the obviously affected area.

Since new users can upload only 4 images, only 4 cropped screenshots are uploaded here.
1.the exported image,
2.scaling=100%,opencl=enabled,zoom=100%,
3.scaling=225%,opencl=enabled,zoom=28%,
4.scaling=225%,opencl=enabled,zoom=52%.




Findings from the screenshots :

  1. The preview agrees almost exactly with the exported image only when Windows Scaling% is set to 100% and Zoom% of the center image is at 100%.
  2. The amount of highlight details tends to decrease slightly with the zoom% of the center preview.
  3. The amount of highlight details is not the same for the cases when opencl in darktable is enabled and disabled.

(Francis Shum) #2

I guess this is a bug and I have reported it. Thanks everyone here anyway.