How to copy the tonal range (histogram) from one b&w image to another?

[Annadan]

Hi there I was just wondering if anyone had any ideas on this one; I've looked all over the web for a solution but havent been able to find one so far.

What I basically want to do is to copy the tonal range/curve of one b&w image to another. I know there is a 'match colour' on PS that achieves something similar with colour images, but I'm using greyscale images only for this project, so obviously that function won't work in this instance.

So any advice? I'm sure there's a simple solution to this but unfortunately I can't for the life of me think what it might be. Thanks in advance!

Anna.

 

[Tom Mann]

Histogram equalization is a special case of what you are seeking. In conventional histogram EQ, the goal is to make the histogram approximately flat, whereas you want to make it have some arbitrary shape.

Histo EQ, and its many variants are commonly used in scientific / engineering / medical applications of photography to present as much info as possible to the user, but are rarely artistically / aesthetically pleasing. In this regard, what you are seeking could be even worse than conventional Histo EQ, or it could be better. It would depend dramatically on the shape you are trying to impress on the original data as well as the shape of the original histogram.


That being said, it's an interesting idea. May I ask, in what way do you think this would be a benefit to photographers?

Cheers,

Tom M