local mean and standard deviation
7 views (last 30 days)
Show older comments
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.....
0 Comments
Accepted Answer
Matt J
on 19 Jan 2013
Edited: Matt J
on 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 );
0 Comments
More Answers (1)
Image Analyst
on 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.
0 Comments
See Also
Categories
Find more on Image Processing Toolbox in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!