akino_germany

I think the main issue is accuracy. The chromaticities calculated by paint.NET from the ICC profile are a little off compared to the chromaticities used to define the profile in the first place: paint.NET eciRGB White x: 0.34576 0.34567 White y: 0.35858 0.35850 Red x: 0.67002 0.67 Red y: 0.33001 0.33 Green x: 0.20998 0.21 Green y: 0.71005 0.71 Blue x: 0.14000 0.14 Blue y: 0.08002 0.08 The sum of the Red x and y components is greater than 1, which they are not supposed to, hence the complaint from libpng.

If you open a PNG (rose_eciRGB.png) with an embedded ICC profile (eciRGB v2) and then save it as a PNG (rose_pdn.png), applications using libpng (like ImageMagick) complain about "invalid chromaticities" in the cHRM chunk. The embedded ICC profile is gone as well. This doesn't happen when saving as a JPEG. Edit: I'm using v4.3.6 but this has happened since at least v4.2.16 PS testImages> magick.exe identify .\rose_eciRGB.png .\rose_eciRGB.png PNG 70x46 70x46+0+0 8-bit sRGB 10840B 0.000u 0:00.000 PS testImages> magick.exe identify .\rose_pdn.png .\rose_pdn.png PNG 70x46 70x46+0+0 8-bit sRGB 9060B 0.016u 0:00.011 identify: cHRM: invalid chromaticities `.\rose_pdn.png' @ warning/png.c/MagickPNGWarningHandler/1746.