Chroma Key export to PNG

jarrod's Avatar


27 Jul, 2011 02:18 AM

In NeoPack, after doing some Chroma Key work, I've been exporting out images with transparent backgrounds as PNG files.
Seemed to be working OK initially.
On closer inspection however, I've found that any spill corrections are ignored if the png has just a transparent background.
If I use a "Colour Transparency", then the spill corrections are exported. (but i have no transparent background.. which is the goal)

examples attached are the same Chroma Key work in Timestone, just one is exported with a "Colour Transparency" of white, and the other with none.

  1. Support Staff 1 Posted by Dino Apolito on 27 Jul, 2011 05:14 AM

    Dino Apolito's Avatar

    That's correct.

    The CK algorithm requires a background for blending purposes which in turn is used for spill replacement. Even when you view an image with the 'transparent' background in the software there is still a background there (it is represented by the traditional white hashed background)

    When you export to png there is no longer a background and therefore the spill replacement cannot occur and you will probably see the green spill as per your example.

    Note if you then add a background in our software at a later stage spill replacement can then occur and all is good.

  2. Dino Apolito closed this discussion on 27 Jul, 2011 05:14 AM.

  3. jarrod re-opened this discussion on 27 Jul, 2011 05:18 AM

  4. 2 Posted by jarrod on 27 Jul, 2011 05:18 AM

    jarrod's Avatar

    In that case then, I need a new comp function for creating Traditional Groups from green screen portraits. ;)

  5. Support Staff 3 Posted by Dino Apolito on 27 Jul, 2011 05:23 AM

    Dino Apolito's Avatar

    We've actually talked about that. i can picture exactly what you're trying to create. It really needs to be a new app

  6. Dino Apolito closed this discussion on 27 Jul, 2011 05:23 AM.

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