title: Variograms on Images - MATLAB
body: <p>I am working on applying geostatistics on Landsat imagery. My focus is on applications of variograms. I will be using n x n windows for generation of variogram plots and texture layers. From an earlier question on stackoverflow <a href="https://stackoverflow.com/questions/681864/how-to-apply-moving-windows-to-a-2d-matrix-in-matlab">How to apply moving windows to a 2D matrix in MATLAB?</a>, I understood that with Image Processing Toolbox it would be wiser and faster to use functions like blkproc, nlfilter, colfilt etc. instead of normal <code>for</code> loop based moving windows. </p>
  
  <p>I see from the help as well as earlier answer that I can integrate other functions to above said functions. But as I have to calculate directional variograms - in EW, NS, NE-SW and NW-SE directions I will have to consider only few pixels(cells of matrix) in front of the central pixel and not all surrounding pixels as in the case of filters. Can anyone suggest how I can go about/or are there functions available to do such operations?</p>