local mean and standard deviation
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sir is there any difference between local mean and mean of a pixel?????????? i need to calculate the local mean and standard deviation of a pixel..... how to do it.... please do reply.....
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Matt J
le 19 Jan 2013
Modifié(e) : Matt J
le 19 Jan 2013
For example, if you want sliding means and stds in all 3x3 neighborhoods
slidingmean=conv2(A,ones(3)/9,'same');
slidingstd=stdfilt(A);
or if you don't have the Image Processing Toolbox
slidingstd=sqrt( conv2(A.^2,ones(3)/9,'same') - slidingmean.^2 );
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Image Analyst
le 19 Jan 2013
I'm not sure you got the terminology right, but the mean of a pixel is just the value of the pixel, because a pixel has a single value unless you're talking about the pixel going across different color channels (in a true color or multispectral image) or across the z dimension in a volumetric image where each slice or plane is the image at a different depth. I don't think you're talking about such images and that you're talking about a normal gray scale 2D image. Correct me if I'm wrong.
The local mean is the mean of several pixels in a region (for example a rectangular 3 by 3 window) around the pixel. The code Matt gave you will do that.
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