[vtkusers] Normalized cross correlation

[David Gobbi]

On Wed, Oct 20, 2010 at 3:11 PM, David Doria <daviddoria at gmail.com> wrote:

> 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.
> http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation

Take a look here:
http://github.com/dgobbi/AIRS/blob/master/ImageRegistration/vtkImageCrossCorrelation.h
For today I can only provide the code, but I'm also working on the
CMake scripts and the old examples... the code itself was written for
VTK 4 but it should give you some idea about the algorithm we used.

   David