I attempted what you mentioned, not sure if I'm not making sense or understanding what you are saying. I'm pretty comfortable with the software but this has been something that has puzzled me for some time and I've just put it on the backburner. Aside from reworking the entire image in grayscale I'm not sure what to do, even in grayscale the height of the texture would have to vary. I feel like there's a possible simple solution and I'm really overthinking this.
-Paul
"The secret to getting ahead is getting started." -Mark Twain