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Re: Color thresholding

Posted by Dimiter Prodanov on Jun 25, 2006; 1:52pm
URL: http://imagej.273.s1.nabble.com/Color-thresholding-tp3702421p3702422.html

Hi Craig,

I have a different suggestion. First, single global threshold is good ONLY for
1 channel (ie. gray-scale) images. To work around
this you can convert tour color space
to CMYK - there is a separate yellow channel.
Make the statistics of the histogram
and then subtract the desired value of the
Y-channel. Then you can convert back to
RGB and see /measure the outcome. Another
possibility is to use the Color Deconvolution
of Gabriel Landini, but it will not save you from
the statistics because you have to
adjust the settings of the plugin to separate well the yellow background.
About the subjectivity: making the image statistics and levering the images to
have similar values; i.e. equal mean intensity of
some of the channels will give you
some way out.

best regards


Dimiter



_______________________________________________________________________
Dr Dimiter Prodanov, MD, Ph.D.

Neural Engineering Rehabilitation Laboratory
(Laboratoire de Génie de la Réhabilitation Neurale)
Département de Physiologie et Pharmacologie
Université catholique de Louvain
Avenue Hippocrate, 54
POBox UCL-5446 / B-1200 Bruxelles -Belgique-
Phone: 00-322-764 5596
Fax: 00-322-764 9422

http://www.md.ucl.ac.be/gren