XnView Software

Using XnView MP 1.5.0 beta 4 on Mac with Intel processor.

When you download the HEIC file from here, open it in XnView MP, and save it in PNG format, the ICC profile of the PNG file will be different from the ICC profile of the original HEIC file.

ICC profile of HEIC file: Display P3
ICC profile of PNG file: Generic RGB profile

This undesired conversion of the ICC profile is bad.

yes strange. I don't understand why your other example is good and not this one. MAcOS API returns a generic profile

It appears that this issue only occurs with images in vertical/portrait format. Horizontal/landscape images do not have this problem.

And the issue only occurs with unprocessed HEIC files that come directly from the iPhone. HEIC files that have been processed by another application, such as GraphicConverter 12, and then opened in XnView MP do not have this problem.

Here are two more test photos of the same subject, taken with the same iPhone:

vertical.heic does have the problem.
horizontal.heic does not have the problem.

BTW, if macOS API is really the culprit, then why doesn't the same problem occur with Apple's Preview.app?

Thanks to your detailed description I can reproduce the problem.

This problem is supposed to be fixed in XnView MP 1.5.1. Please check and confirm the bug fix here.

The problem is fixed in v1.5.1. Thank you very much!