On Mon, Oct 18, 2010 at 10:03 AM, David Doria <<a href="mailto:daviddoria@gmail.com">daviddoria@gmail.com</a>> wrote:<br>><br>> Has anyone written a normalized cross correlation filter? This seems<br>> like a pretty standard thing to do that is missing from VTK.<br>
><br>> I started one here:<br>> <a href="http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation">http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation</a><br>><br>> if anyone wants to help.<br>
><br><br><br>I wrote the algorithm. Unfortunately... it is VERY slow. I haven't even been able to test it at all because even with a small (11x11) kernel, it is taking about a minute just to do ONE ROW of the correlation on a 400x400 image. I am clearly doing something very wrong with the vtkImageData things. Would anyone mind taking a look to see if they can see a better way to do some of the core functions (SubtractMean, for example). I have some DeepCopy's, but I didn't see a way around them, as I needed to actually modify the data while keeping it intact in the original image.<br>
<a href="http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation">http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation</a><div><br>Thanks,<br><br>David <br></div>