How to combine a L with RGB

[Emanuele]

Hi all.

Stupid question here but I really have tried everything.
I have extracted the Luminance channel from an RGB image taken from the web.  Now I worked on the L, enhancing it a bit, and I want to recombine the image, using the new L as Luminance and the original image as RGB (for color only)

How can I do it in PI? I know how to do it in Photoshop....
If i use LRGBCombination it tells me that it cannot work on Greyscale images.

Thanks.
E.

[Jack Harvey]

Open the Channel Combine tool, select the L,a,b button, uncheck a and b and put your new Lum in the L space.  Drag the triangle onto the image in which you wish to insert your new Lum.

[Emanuele]

easy peasy!!

Thank you Jack!

[Nocturnal]

Also keep in mind that most processes can operate on just L so there may not be a need at all to extract, process and re-apply it. You can choose to display just the L component of a color image.

[Jack Harvey]

Good Point Sander