Posted by
Gluender on
May 13, 2008; 9:55am
URL: http://imagej.273.s1.nabble.com/Filtering-certain-color-range-tp3696226p3696235.html
>Hi there everyone,
>
>I would like to know if it is possible to subtract or filter a certain color
>range. I have attached a photograph of a core(acquired while drilling the
>hole looking for oil). From the image, three different major features (in
>terms of color) can be seen, light brown, dark brown and gray.
>
>
http://www.nabble.com/file/p17182225/2010.00-2020.00%2Bm.jpg>2010.00-2020.00+m.jpg .
>
>What I would like to do is to know the total height of the sand(light and
>dark brown) in the image removing the gray stuff which is shale/clay.
>Therefore, if I could filter the gray stuff out, I can then plot a profile,
>knowing that the low value(or black) is the shale/clay and the rest is sand.
>
>The problem I have now is, when I plot a gray scale profile, it will not be
>possible to differentiate the shale from sand as the shale seem to be
>brighter than the dark brown sand.
>
>Any advice on this matter is very much appreciated. Thanks guys/gals.
>--
>View this message in context:
>
http://www.nabble.com/Filtering-certain-color-range-tp17182225p17182225.html>Sent from the ImageJ mailing list archive at Nabble.com.
Surely you may "filter" your images but be aware that with RGB-images
there is no spectral filtering as you may know it from filtering
coloured light. With this respect it is even questionable whether the
term "filter" is adequate.
First you should realize what RGB means, then you may look for
certain combinations in the three colour channels that characterize
the relevant regions of your images. Then you can separately treat
these regions...
HTH
--
Herbie
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