I'm looking for a tool / plugin /script / procedure / expression /whatever that would sample the color of a user defined pixel in each frame of the comp so I could use that to match the color of something else to that color. Is there such a thing? One might think this is a common thing to do but I've never seen it anywhere...
Thanks for any advice!
Expressions, How to, Resources, Scripting, User interface or workspaces
In an expression, you can use sampleImage(point, radius = [.5, .5], postEffect=true, t=time)to do so. With the point control you can easily let the user select a certain pixel. Return value is a 4-item array [r,g,b,a], which you can use to drive the other thing. Read more about this in expression reference:https://helpx.adobe.com/after-effects/using/expression-language-reference.html *Martin
Given how AE works there cannot be some generic color sampling tool as any corrections you plan on doing would have to be applied via effects, anyway. That being the case, chances are you would need an expression with the sampleImage() function linked to the parameters of color correction effects or some such thing. There's no generic answer here. You have to be very specific and explain what you are trying to match and how you plan on applying the color.