[Numpy-discussion] shift for optimal superimposition of two 3D matrices according to correlation computed using FFT

2009-04-07 Thread Klaus Kopec
Hello everybody, I have two 3D density maps (meaning volumetric data, each one essentially a IxJxK matrix containing real values that sum to one) and want to find translation of between the two that maximises correlation. This can be done by computing the correlation between the two (correlati

Re: [Numpy-discussion] shift for optimal superimposition of two 3D matrices according to correlation computed using FFT

2009-04-07 Thread Zachary Pincus
> I have two 3D density maps (meaning volumetric data, each one > essentially a IxJxK matrix containing real values that sum to one) and > want to find translation of between the two that maximises > correlation. > This can be done by computing the correlation between the two > (correlation theor

Re: [Numpy-discussion] shift for optimal superimposition of two 3D matrices according to correlation computed using FFT

2009-04-09 Thread Klaus Kopec
> Does it work to use a cutoff of half the size of the input arrays in > each dimension? This is equivalent to calculating both shifts (the > positive and negative) and using whichever has a smaller absolute value. no, unfortunately the cutoff is not half of the dimensions. > Alternately, you

Re: [Numpy-discussion] shift for optimal superimposition of two 3D matrices according to correlation computed using FFT

2009-04-09 Thread Zachary Pincus
>> Does it work to use a cutoff of half the size of the input arrays in >> each dimension? This is equivalent to calculating both shifts (the >> positive and negative) and using whichever has a smaller absolute >> value. > no, unfortunately the cutoff is not half of the dimensions. Explain more