Help requested: Pixel area counting with "magicwand&quo

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madscientist
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Help requested: Pixel area counting with "magicwand&quo

Post by madscientist »

I am working on digital images of brain sections and I need to know the area of observed degeneration. I can select an area of similiar color and intensity by using the magicwand tool which is very helpfull (as other programs require me to first transform the image into a threshold). However, problem is Photoshop does not give a readout of the total number of pixels (area) that has been selected using the magicwand (or any other selection tool.)
Is there any way I can get that information, and also get a output file as tabbed text file?
I am in desperate need for this and i belive this is not a very tough problem to crack, however as I lack any formal training and experience in programing I have basically hit a wall.
I can get around this problem but the thing is I have to handle about 300 (1360X1024pixel) images per sample and doing it in a roundabout way will take me days to calculate the individual areas manually for a single specimen.
I would appreciate any hints to solve this.
Madscientist
ignorance is random, intelligence is not

toby
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There is one easy way

Post by toby »

Hi madscientist

Save selection. Threshold. Histogram.

Let me know if this helps. Note that the magic wand selection has soft edges (with AA enabled), hence the threshold operation. (If you want a method of counting "coverage" taking into account partially selected pixels, I can easily modify my Count Colours plugin to do this for you. http://www.telegraphics.com.au/sw/#countcolours)

Toby

madscientist
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Joined: Wed Jan 12, 2005 5:06 pm

Post by madscientist »

Thanks Toby, I have found your suggestion helpful, but is there any way that I can get the pixel count value be exported as a tabbed text file? (i finally intend to import all my collective data in MS excel).

In the mean time I will experiment with the "count colors" plug-in that you have developed.

Thanks a lot,
madscientist.
ignorance is random, intelligence is not

toby
Plugin Master
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Joined: Sun Nov 10, 2002 11:42 am
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Post by toby »

madscientist wrote:Thanks Toby, I have found your suggestion helpful, but is there any way that I can get the pixel count value be exported as a tabbed text file? (i finally intend to import all my collective data in MS excel).
Hi madscientist

I am still unclear what you're trying to do - can you describe in more detail?

For instance, when you say "pixel count be exported", the count is just one small value. Clearly you are doing something repetitively, and unless the plugin can follow the same method automatically and generate a quantity of tabular data thereby, spreadsheet export makes no sense to me. Can you clarify the method you are using so we can consider ways of automating it?

Toby

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