Add grain, luma based?

[45tripp]

How would I go about adding grain to only the dark areas of a picture?

ty

[Didée]

For example, in the same way like this here (http://forum.doom9.org/showthread.php?p=1033464#post1033464).
Just exchange "b = source.denoise()" with "b = source.AddGrainC(...)"

[45tripp]

thanks,
it's perfect