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Re: Black/Yellow Ratio Analysis

Posted by Herbie on Sep 30, 2016; 2:29pm
URL: http://imagej.273.s1.nabble.com/Black-Yellow-Ratio-Analysis-tp5017259p5017261.html

Good day Meg,

I assume that you have RGB-images and as the name implies, they don't
show an explicit yellow channel...

To extract the yellow areas you may have a look at
"Image > Adjust > Color Threshold"
or at the plugin "color deconvolution" of Gabriel Landini
<http://www.mecourse.com/landinig/software/software.html>

There are other approaches/plugins as well.

The greater problem appear to be the "black" area. For the purpose of
the black area extraction it would be helpful to see a typical image.

Best

Herbie

::::::::::::::::::::::::::::::::::::::::::::::::::
Am 30.09.16 um 15:54 schrieb Margaret Grace James:

> Good afternoon,
>
>
> I am an Ecology undergraduate and for my dissertation I need to
> analyse around 800 separate images of hoverfly specimens. I wanted to
> ask what is the most accurate and time efficient way to be able to
> measure the amount of black and yellow in a section? I am
> investigating the different ratios of black to yellow in hoverfly
> abdomens.
>
>
> I have previously drawn a freestyle shape around first the black
> 'stripe' and hit Ctrl+M, then repeat for the yellow, then entered the
> figures into a spreadsheet I have set up to calculate the ratio. With
> a very large sample size I wanted to ask if there is a better way of
> doing this, I am very new to ImageJ and find most of its functions
> are way over my head!
>
>
> I would genuinely appreciate any and all advice you have.
>
>
> Many thanks,
>
>
> Meg
>
>
> -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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