App UI - icon - file type - add more sizes to avoid interpolation

[user0]

XnViewMP 1.8.3 64bit
Windows11 (24H2), display resolution 3840x2160, win scaling 150%

App UI - icon - file type

Icon scaling
When Windows displays your app's icon, it will look for an exact size match first. If there is no exact match it will look for the next size above and scale down. Including more icon sizes with your app means Windows will more often have a pixel-perfect match, and reduce the amount of scaling applied to scaled icons.

XnViewMP has filetype icons of the following sizes: 16, 32, 48, 256px which are used as follows:

• source 32px icon interpolates to
  - 20px icon at 125% win scale
  - 24px icon at 150% win scale
  - 28px icon at 175% win scale

• source 48px icon interpolates to
  - 36px icon at 225% win scale
  - 40px icon at 250% win scale

• etc

Check how messy downscaled icons look:
- test_icon_1 vs test_icon_2
- 24px icon: bmp_1 (original 32px-downscaled-to-24px) vs bmp_2 (manually created 24px)

win_icon_filetype_and_dpi_scale.png

test_icons.zip

to reproduce
1. change win dpi scaling
2. rebuild icon cache
sometimes it is also required to rename file/parent folder to force file explorer to use correct icon
3. open folder with test icons in win file explorer (in Details, List or Small icons View)


Suggestion

• add more sizes to file type icons to avoid interpolation at different win dpi scales
  icons have to be manually adopted to the desired sizes, but just downscaled from bigger one
  • minimum: 24px
    I have created one as an example
  • maximum: 20, 24, 28, 36, 40, 56px

ref
Construct your Windows app's icon
Icons (Design basics)





Example

other_apps_icon_filetype.png

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