GIMP Version: 3.0.4
Operating System: Windows
GIMP Experience: New User

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Is there a 'newbie' method that will identify the CIE L*a*b* shade of scans taken with an Epson ET-2810 scanner? TIA for any advice.

The images will be RGB - Gimp is a RGB editor, although the color profile, the something.icc can vary. When you import an image there is usually a choice to keep-existing or convert-to-GimpRGB Probably best to keep.



You can decompose Colors -> Components -> Decompose and select LAB from the Color Model Drop down menu. (1) see: https://docs.gimp.org/3.0/en/plug-in-decompose.html Greyscale layers which you can edit then Recompose.

If you install the gimp_gmic_qt plugin http://www.gmic.eu then that also has a decompose filter (2) also...
...an interactive curves filter with a LAB option (3)

What are your scans ? Are they negatives ? There will be users more experienced than me for that purpose.

Thanks rich2005,

They are scan in high res of very old postage stamps that have numerous shades. I'm endeavouring to catalogue against the attached research document.

Ouch I can not see anything in Gimp for that. A quick look at ImageMagick - nothing obvious.

Try this scientific application: Two versions ImageJ https://imagej.net/ij/ and an enhanced version fiji https://imagej.net/software/fiji/downloads
In the fiji plugins menu to look for Color Inspector 3D That gives values under the cursor for RGB and LAB

A quick scan into Gimp, export as a png - looks like this using fiji



Edit: A closer look and if you select the histogram option and then click LUT you get a table of Lab colours

rich2005 - Thank you. That's helpful and will get me to the next stage I think.