Alpha channel should be 1 by default, rather than 0

AcademySoftwareFoundation / OpenColorIO

A color management framework for visual effects and animation.

https://opencolorio.org

BSD 3-Clause "New" or "Revised" License

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Alpha channel should be 1 by default, rather than 0 #1781

Open doug-walker opened 1 year ago

doug-walker commented 1 year ago

Currently if you make an apply call with a source ImageDesc that is RGB and a destination that is RGBA, the A value of the destination is 0. This is inconvenient since most clients will need to then set the alpha channel to 1 to make the image visible.

The proposal is that the alpha channel input value should start out as 1 in this scenario.

This would go into OCIO 2.3 to avoid changing behavior of the 2.2.x branch.

royashams commented 11 months ago

I would be interested in taking a look at this issue for aswf devdays!

pennelee commented 2 months ago

Hi @doug-walker , Is there a sample test case that exists already that has destination RGBA and shows the issue where alpha is 0? Thank you!

doug-walker commented 2 months ago

Any CPUProcessor that starts with RGB input and produces RGBA output will have the A set to 0. You could start with a ColorSpaceTransform between any two color spaces to generate the Processor.