Re: Measuring RGB average values in an ROI

Posted by Jon Harman-3 on Feb 18, 2015; 5:26pm
URL: http://imagej.273.s1.nabble.com/Measuring-RGB-average-values-in-an-ROI-tp5011644p5011668.html

Hi Wayne,
Thanks, that is easy.  My next question is:
Is there an RGB multiply macro or plugin that multiplys the RGB channels
by different scalers and correctly deals with the 8 bit values, i.e.
prevents going over 255.

Jon

On 2/17/2015 4:17 PM, Rasband, Wayne (NIH/NIMH) [E] wrote:

> On Feb 17, 2015, at 6:52 PM, Jon Harman <[hidden email]> wrote:
>>
>> Hi,
>> Just checking if there is a simple way to get the average R,G,B values in a color image inside of an ROI.  I know that I could split the image into R, G, B images then copy the ROI into each and calculate the average gray.  That seems to be a pain.  Is there anything easier?
>
> Use the Plugins>Analyze>RGB Measure command, which runs the MeasureRGB macro, available at
>
>      http://imagej.nih.gov/ij/macros/MeasureRGB.txt
>
> Or convert the RGB image to a composite image using Image>Color>Make Composite and press “m”, “>”, “m”, “>” and “m”. “m” is the keyboard shortcut for the Anlayze>Measure command and “>” is the keyboard shortcut for Image>Stacks>Next Slice.
>
> -wayne
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