LAB color

[sallustio]

I'm a textile designer using a fabric printer that works with LAB colors. I have been placing my TIFF files in index mode and sending along a separate spec of LAB colors for each individual color. The printer suggested if I could put my file directly into LAB colors they would have to manual do it and that would save $$$ on making samples. I've seen a lot of reference online to LAB and GIMP. I've tried Decomposing but that gives me a gray scale. How do you covert that into LAB colors? Thanks

[ofnuts]

You're looking at the wrong place. The decomposition you see in Gimp (Color/Components/Decompose) is used to tweak the image using specific colorspaces (HSV, LAB or else). Typically you decompose the RGB image, edit one of the layers of the decomposition, and recompose in an RGB image.

What you want is a TIFF saved in the LAB colorspace. Gimp can't do that, but here are utilities to convert a RGB TIFF into a CIELAB one. It seems that ImageMagick can do it.