Posted by
Anderson, Charles (DNR) on
Feb 24, 2015; 4:45pm
URL: http://imagej.273.s1.nabble.com/Re-best-way-to-select-a-range-of-colors-tp5011725p5011753.html
Rita,
Try Analyze | Tools | Synchronize Windows.
Then use the Color Space Converter plugin from RGB to LAB white=D75 separate images.
The resulting L* window has values constrained 0-100.
Draw a rectangular region of interest on the L* image.
Analyze | Histogram will give you min, max, mean, mode, sd for the L* image region.
Click on the margin of the a* image.
Analyze | Histogram
Click on the margin of the b* image.
Analyze | Histogram
Beyond that, I don't know what you mean when you say you want to "find the exact value".
Charles
-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of Rita Goncalves
Sent: Monday, February 23, 2015 3:36 PM
To:
[hidden email]
Subject: Re: best way to select a range of colors
Good night Curtis,
Thank you for your comment. The reason why I wrote in Portuguese was because I saw the surname of Rodrigo and I thought he was Portuguese, so I tried to speak with him because when two persons speak the same language is easier. However, he cames from Argentina, he speaks Spanish.
So, I'm gonna try again, this time, in English. A few days ago, I wrote here, in the mailing list, a message with the title "Colorimetric Parameters" as you can see if you check it, because I have many doubts about how to analyze color parameters.
I am an Agronomic Engineer and I am studying the color of fruits. When I am analyzing an image, I need to know the exact value of L*, a* and b*. However, I don't understand how i can do it because, for instance, 0 < L* < 100, and in the color threshold window, the range varies between 0 and 255. I don't know how to convert the 0-255 scale into the Lab scale. When I use the Color Space Convert it appears three windows but I can't find the exact value.
I'm sorry if this is a basic question but I found ImageJ just a month ago.
Thanks for helping me.
Regards,
Rita
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