[vtkusers] Normalized cross correlation

[David Gobbi]

On Wed, Oct 20, 2010 at 3:11 PM, David Doria <daviddoria at gmail.com> wrote:
> On Mon, Oct 18, 2010 at 10:03 AM, David Doria <daviddoria at gmail.com> wrote:
>>
>> Has anyone written a normalized cross correlation filter? This seems
>> like a pretty standard thing to do that is missing from VTK.
>>
>> I started one here:
>> http://github.com/daviddoria/vtkImageNormalizedCrossCorrelation
>>
>> if anyone wants to help.
>
> 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

Hi David,

One of my fellow PhD students wrote one, I'll be posting it on git
later tonight or early tomorrow.  Not sure if it does the same thing
as yours.

  David