Posted by
Robert Baer on
Sep 12, 2009; 11:19pm
URL: http://imagej.273.s1.nabble.com/Counting-color-pixels-tp3691188p3691189.html
My guess is that you have not operationally defined what you mean by red and
blue. Computer images are composed of a 3 byte definition in the red,
green, and blue channel which means that there will be shades of red and
blue that may contain a small amount of green. Likewise, grey and white
pixels can contain significant red and blue content. This makes your task
potentially non-trivial even if the original red and blue colors were added
using pseudocoloring values in the red and blue channels of the image.
One of the first thing to do to get an idea of the problem you face is to
do: iamge | color | split channels and examine the areas that were
previously blue or red. The next thing that I would recommend is taking a
look at Gabriel Landini's Threshhold_colour plugin described on the ImageJ
Wiki,
http://imagejdocu.tudor.lu/doku.php?id=plugin:color:threshold_colour:start
and available on his site,
http://www.dentistry.bham.ac.uk/landinig/software/software.html It may be
that looking at your image in HSB mode will give you additional insight into
how to segment it.
HTH,
Rob
----- Original Message -----
From: "Smileyy1585" <
[hidden email]>
To: <
[hidden email]>
Sent: Saturday, September 12, 2009 4:01 PM
Subject: Counting color pixels
> Hi,
>
>
> I am new to this forum but I'm having some difficulty with the ImageJ
> program. My goal is to take color doppler images and to count the colored
> pixels within a certain area. The main colors I am looking for are red and
> blue, but the color ranges from light to dark red and blue. What makes
> things difficult is that the background is black, light and dark grey.
> Basically I want to count the colored pixels and divide it by the total
> number of pixels of a chosen area.
>
> I keep seeing that this is possible with Image J, but I have not been able
> to make this work. Any help would be appreciated. Thank you!
> --
> View this message in context:
>
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