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rvio -unpremult makes background white

I am trying to use rvio to unpremultiply an image.  When I do

rvio premultiplied.exr -outunpremult -o unpremultiplied.exr

It turns all the pixels with 0 alpha white, which is not what I want.  All the pixels with 0 alpha should just stay the same color.  Any suggestions?

Thanks.

4 comments

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    Jon Morley

    Hi Chad,

    Can you please share with us which version of RVIO you are using (and on which platform)?

    Thanks,
    Jon

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    Chad Vernon

    I am using rvio 4.0.11 on OSX 10.8.5.

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    Jon Morley

    Hi Chad,

    I was able to reproduce the issue you described. I think the best course of action for you is to write session files to feed to RVIO. The "-outunpremult" is broken and it isn't really the best way to get what you need even if it did work. Instead it makes more sense to build a session file and insert a unpremult node into the graph to convert your source.

    If you want to try this interactively in RV please :

    1) Open your source

    2) Select your source from the Tools -> Session Manager

    3) Click the plus icon and choose "New Node by Type..."

    4) Enter "UnPremult" and press "OK"

    Then you should see the results and be able to save your session to send to RVIO. I am attaching an example session.

    Thanks,
    Jon

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    Jon Morley

    Adding sample session here. Attached linked below.

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