Not sure if this post belongs in the expressions forum, but I'm not looking for help writing the expression itself, just in trying to gather the data that will drive it, so I'm going to post it here.
What I'm trying to do is sample the brightness of a given pixel area on screen, and then use that brightness to adjust the brightness of a separate layer -- kind of like a parenting idea, but with brightness instead of position.
Is there a way to get a numerical value for the grayscale value of a pixel in aftereffects? I'm trying to think of a way to do it, and can't decide if it's really easy and obvious but I'm missing it, or if the reason I can't figure it out is because it's actually hard.
Any thoughts from the group would be much appreciated.
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