Re: Black/Yellow Ratio Analysis

Posted by Herbie on Oct 02, 2016; 4:00pm
URL: http://imagej.273.s1.nabble.com/Black-Yellow-Ratio-Analysis-tp5017259p5017269.html

Dear Meg,

attached please find a possible segmentation result based on color.

Here are the processing steps:

1.
Remove the background by using an appropriate "Color Threshold".

2.
Select the isolated object (insect).
 > 17_whole
Measure the area (number of selected pixels)
in my case > 2 178 330

3.
Select what you judge being yellowish by using an appropriate "Color
Threshold".
 > 17_yellowish
Measure the area (number of selected pixels).
in my case > 957 892

4.
Subtract the yellowish area from the total area which gives you the
grayish area.
in my case > 1 220 438

Evidently there is little chance for "Color Threshold"-parameters that
are universally applicable. In short, you will have to individually
determine adequate settings... Hence, be prepared that several hundreds
of objects may take some days to analyze.

HTH

Herbie
(Sorry, but my actual name is not Herbert.)

::::::::::::::::::::::::::::::::::::::
Am 02.10.16 um 17:05 schrieb Meg James:

> Hi Herbert,
>
> Thank you for the advice, I wouldn't dream of using a phone for
> serious analyses! I am doing my undergraduate dissertation andone can
> only use the equipment available to me, I have no access to better
> photography equipment. I appreciate you taking the time to help me.
>
> Many thanks, Meg
>
> -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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