Pixels with RGB>0 and A=0 are still displayed about tev HOT 2 CLOSED

Hi Baptise,

this behavior is intentional, as the RGB values of EXR images should be interpreted as having pre-multiplied alpha. Photoshop and Gimp are wrong.

For a practical use case, consider composing the image of a flame onto some background. The alpha channel of the flame corresponds to its opacity, whereas the RGB channels correspond to its emitted light. Since flames don't really absorb light, their opacity---i.e. alpha channel---should be (roughly) zero, while the RGB values should still be very bright. In this case, the flame should be displayed, despite its zero alpha value.

Check this example image of exactly the scenario I describe. The candle flame is meant to be visible despite its alpha value of zero.

See also the comment by Sami in issue #87 .

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Alright, thanks for clarifying!

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