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circular cross correlation

Started by jasg February 26, 2007
  I need a cross correlation, which is circular along teta-axis and linear
along ro-axis 
             XC(H', R') =  Σ Σ  F(p + H', teta + R'). G(p,teta )

 I have tried several methods but without satisfactory results. Also, I
have used the function "imfilter", which does a circular correlation but
the result is always the same: bad.
 I know that teta-axis-circular and p-axis-linear cross-correlation can
readily be achieved by zero-padding only the p-axis direction
and performing a circular cross-correlation with an FFT-
based algorithm but I don�t know how.I think i Do bad the zero padding but
I�m not sure.
 I would be very grateful if somebody could help me. Thank you




On Feb 26, 6:00 am, "jasg" <jorgesanchezgar...@hotmail.com> wrote:
> I need a cross correlation, which is circular along teta-axis and linear > along ro-axis > XC(H', R') =3D =CE=A3 =CE=A3 F(p + H', teta + R'). G(p,tet=
a ) Sorry, I don't understand what you are trying to do. Are you trying to generate a stochastic vector with a certain correlation property? Or are you trying to make a filter with a certain spectrum?
> > I have tried several methods but without satisfactory results. Also, I > have used the function "imfilter", which does a circular correlation but
Sorry, I don't know what imfilter is. Julius
 I am working with image registration. I work with images(matrix, no with
vectors). For the correlation I use two matrix (images) in polar
co-ordinates (r,teta). My problem is that I need to do a two-dimensional
cross correlation, which it is circular along teta-axis and linear along
r-axis.
 Imfilter is a function of Matlab that do a circular cross correlation.  

Jasg