ICNS always darker than original PNG

Zirifio's Avatar


04 Apr, 2017 08:42 AM

Image2icon is a great app, but there seems to be an issue:
No matter what colour profile I use for the source PNG, Image2icon always turns out the colours darker (more saturated) in the final ICNS.

- I’ve tried different standard colour profiles (like sRGB, Generic RGB etc) for the PNGs
- and different ways of saving the preview image (Mac, Windows, document profile, no pro)
- I use Photoshop to create the PNG’s
- all in Mac OS 10.10.5 Yosemite

The difference is visible when both ICNS and original PNG are opened in (for example) Preview or sitting on my desktop, so it’s not a preview issue in Photoshop.

The colour differences don’t occur when using other ICNS-apps (Iconie, Iconographer)

What colour profile does Image2icon use?

  1. Support Staff 1 Posted by Danilo Bonardi on 05 Apr, 2017 07:55 AM

    Danilo Bonardi's Avatar


    Image2icon to a gamma correction on the icns to make them look better when used on files. MacOS revert the gamma correction for certain sizes ( from 128 to 1024 if I remember correctly ).


  2. 2 Posted by Zirifio on 05 Apr, 2017 12:26 PM

    Zirifio's Avatar

    So, if I understand this correctly, Image2icon ‘corrects’ the originals on purpose?
    Seems an odd way of working. A conversion should always be as close to the original as possible, isn’t that the rule?

    A suggestion: make an ON-OFF button for this effect (and call it the ‘magic shine button’ or something ;-), so that at least one has a choice.

    Sometimes the design benefits from the app’s gamma correction, but more often than not my original looks exactly right in all sizes, and Image2icon messes it up in the final step (colours are off, the image looks bloated in small sizes). It’s pointless to make changes to the original to make up for this, because you can’t predict how Image2icon will handle the changes and either the big sizes or the small sizes will suffer from it.

    I did notice the gamma correction to bigger sized icons by Mac OS (to icons made in Image2icon that is, Apple's standard icons are not affected by it). But I can’t see what purpose this is serving.

    For the moment I think I’ll switch to another, more predictable app.
    But thanks for the explanation anyway, it cleared up a few things.

  3. Support Staff 3 Posted by Danilo Bonardi on 06 Apr, 2017 08:39 AM

    Danilo Bonardi's Avatar


    we can introduce a preference for turning gamma correction off, but I don't how many will be interested: Image2icon is a "consumer" app and I think people will be more interested in icns files which look good on their desktops.

    If I remember correctly if you export as iconset the gamma is not corrected.


  4. 4 Posted by Zirifio on 06 Apr, 2017 09:23 AM

    Zirifio's Avatar

    I understand. Thanks for the iconset tip!

  5. Danilo Bonardi closed this discussion on 06 Apr, 2017 09:34 AM.

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