Re: Colour removal

Posted by jerie on
URL: http://imagej.273.s1.nabble.com/Colour-removal-tp5014344p5014357.html

Hi Howard,

On Tue, Sep 15, 2015 at 6:25 PM, Howard <[hidden email]> wrote:
[ on example image] ...<
http://imagej.1557.x6.nabble.com/file/n5014344/wing.jpg> we want to remove
the dark areas (greys and blacks) that constitute the veins...want to
quantify the average colour of different areas demarcated by the dark wing
veins...Image likely vary in brightness and in other ways...Whether HSB is
a better colour space... is never discussed.

if you subtract background,
run("Subtract Background...");

You can threshold and segment the wings into 4 major regions each wing.
Using the 'analyze particles' command, you can add these regions to the ROI
manager
run("Analyze Particles...", "size=100 show=Nothing exclude include add");
and for each ROI generate a Color Histogram.

to measure the HSB Histogram, convert your image into HSB, then use
run("HSB Stack");
run("Stack to RGB");
run("Color Histogram");

The subtract "Subtract Background..." should make it relatively robust
against changes in background intensity. There are other options to
pre-equalize intensity fluctuations.

With only one image its difficult to say how much sense the measurements
would make. I am happy to go into a second round with a small number of
images that show the variance of the image quality.

Kind regards,
Jens

Dr. Jens Rietdorf, visiting scientist @ center for technological
development in health, Rio de Janeiro, Brazil.
http://br.linkedin.com/pub/jens-rietdorf/6/4a3/189/

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