Natron - Non-faithful export


I am a beginner with Natron

I inserted on a video made under blender, a smoked video that was on a green background. I changed its color. The preview is good.
But the exported video does not match… A big white border appears.

Am I doing something wrong?

Thanks for your help

I use: Natron version 2.3.15 Release on Ubuntu 20.04

What does the Multiply node do?

The video original of the smoke is gray (on a green background). The saturation filters had no effect on this B&W image. I had to saturate it with a brown color to better integrate it on the floor. That’s what the multiplication filter is for.

Does your source footage have an alpha? If not check on the auto alpha box in the Read node of your footage that isn’t a greenscreen element.

I found this option in the “Merge” module itself. And indeed, it removes the white border… :slight_smile:

Thank you very much !