09-19-2020, 07:57 AM
If you use 32-bit precision images in Gimp, the PNG export uses the 16-bit PNG variant by default, which of course nearly doubles the size. Either
- Check your options and make sure that you are not "promoting" your image to floating point when loading (Edit>Preferences>Image import and export).
- Export a PNG, choose 8bpc RGBA as the output format (instead of "automatic pixelformat"), and click "Save defaults.