Calculate Lab values for all the particules

Hello, I am Dan.

I am new in this forum and I am not an expert at all in Image Analysis, so my apologize in advance if my question is trivial

My language is not English. if my English is difficult to understand,please tell me that. i rewrite about this or add more information.

I have several soybean pictures and I would like to measure

「The colors ("Lab"values) of these spots」

This is an example picture before Color Threshold

This is picture after Color Threshold

Now I would like to get L, a, b values for the all spots.

Anyone know how to do that (if possible…)?
Thank you very much in advance for your help!

Works Cited:Calculate RGB values for all the particules

Hello Dan -

After you have performed Color Threshold..., run

Process > Binary > Convert to Mask
Analyze > Analyze Particles...

When you run Analyze Particles... you should probably
set a lower “Size (pixel^2):” limit of something like 10,000.
Also, make sure that “Add to Manager” is checked.

Clear the Results table (but do not clear the ROI Manager),
and reopen your original color image.

Then run

Image > Type > Lab Stack

You will now have a three-channel stack, with the channels being
“L”, “a”, and “b”.

Select each channel, one by one, and click Measure in the
ROI Manager. Each click of Measure should add 100
measurement rows to the Results table – 300 total, 100
apiece for each of the “L”, “a”, and “b” channels.

Before running Measure you can run

Results > Set Measurements...

from the Results-table menu bar to select the specific
measurements you want to make.

Thanks, mm

Thanks mountain_man

I can measure “Lab” values but the values don’t accord with real picture color.

For example, a soybean’s color values is 100(L) , 0.01(a) , 0.01(b).
it dose not accord with Picture’s color.

Do you know how to measure Lab values which accord with picture color.
I’d appreciate it if you could answer my questions.

I think you did the Lab conversion on the thresholded binary image. But as @mountain_man mentioned you need to do this on the original color image

Thereafter, you can use the created ROIs in the three channels which should show up as three gray-scale channels

Big Thanks,I solved it.