Hi. Just learning Photoshop (finally) and working on a project and stumbled onto a problem:

I have two different desaturated RGB images, bump maps actually. The "source" image has a a wider range of values than the "destination" image. Their layouts are different but I want to apply the source image's histogram and colors to the destination image without using a healing brush or whatever. Is this possible?

i suppose you could just paste one image over the other, and use a layer that adjusts the levels on the image that you want to change.

You can also try another method very similar to Karosnikov's - use a Levels Adjustment Layer (like shown in the image above) and make your adjustments to your Source image. Then literally click and drag the Adjustment Layer (from the Layers Palette) off of the Source image and onto the Destination image - there's your exact copy of the Histogram adjustment.

Good luck-
-Lew ;-)