Re: Pixel count via RGB range

Posted by Gus on Sep 09, 2010; 7:45pm
URL: http://imagej.273.s1.nabble.com/Pixel-count-via-RGB-range-tp3686979p3686984.html

Hi Komal,

Thanks, that suggestion helped a lot. I converted the image to binary so
that now there are only 2 values: 0 (background) and 255 (vegetation).

I've been using the 'Analyze Particles' tool but the results aren't exactly
what I expected. For example, the total number of pixels in the report
doesn't match that given in the image info. I've asked it to include holes
and not to exclude edge, which to me should mean that it's analyzing every
pixel.

Seems straight forward at this point considering there are only 2 values.
All I need is the count for each.



On Thu, Sep 9, 2010 at 2:39 AM, komal asrani <[hidden email]>wrote:

> Hello
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> I have implemented the concept of pixel count for binary images. I think in
> regard to your query, is it possible to work in binary?Otherwise, collect
> the values for each band and then compare
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> On Thu, 09 Sep 2010 05:17:16 +0530  wrote
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> >Hello,
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> I'd like to use this software for digital vegetation profiles. The idea is
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> to place a 0.5m x 0.5m white background (drop cloth, poster board,etc.) in
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> field plot and take a picture of it from a certain distance. I'd then crop
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> out just the half meter square area to analyze.
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> I suspect that the leaves and twigs would have a fairly small RGB range, as
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> compared to the white background, that I could specify and then have ImageJ
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> count the pixels in that range. All that's left is to divide by that number
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> by the total pixels to get a percent cover of vegetation.
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> If someone could point me in the right direction on how to do this with
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> ImageJ I would be very grateful.
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> Thanks!
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> With regards
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> Komal Asrani
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