support for 2d convolutions

[GoogleCodeExporter]

I'm requesting a new feature be added to EJML to perform 2d matrix convolutions 
similar to the octave function conv2.  For example, in octave, given a 'data' 
matrix and a 'feature' matrix, you'd execute the following:

    feature = flipud(fliplr(squeeze(feature)));
    convolved_data = conv2(data, feature, "valid");

The slow element-wise algorithm would be:

  convolved_data = zeros(size(data,1) - size(feature,1) + 1, size(data,2) - size(feature,2) + 1);

  for iy = size(convolved_data,2)
    for ix = 1:size(convolved_data,1)
      for fy = 1:size(feature,2)
        for fx = 1:size(feature,1)
          convolved_data(ix, iy) += data(ix+fx-1,iy+fy-1) * feature(fx, fy);
        endfor
      endfor
    endfor
  endfor

Original issue reported on code.google.com by cjbe...@gmail.com on 15 Sep 2012 at 4:26

[GoogleCodeExporter]

I'm going to think about this request a bit more.  The focus of EJML is on 
linear algebra.  2D convolutions fall under signal processing.  Having 2D 
convolution capability would be useful in a few applications where EJML is 
applied...

Original comment by peter.ab...@gmail.com on 17 Sep 2012 at 6:44

[GoogleCodeExporter]

Going to reject this feature request because it is outside of scope.  There is 
some convolution code in BoofCV, but it isn't general purpose yet.

Original comment by peter.ab...@gmail.com on 4 Dec 2012 at 3:55

• Changed state: WontFix
• Added labels: Type-Enhancement
• Removed labels: Type-Defect