# circular cross correlation

Started by February 26, 2007
```  I need a cross correlation, which is circular along teta-axis and linear
along ro-axis
XC(H', R') =  &#931; &#931;  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
and performing a circular cross-correlation with an FFT-
based algorithm but I don&#2013266100;t know how.I think i Do bad the zero padding but
I&#2013266100;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

```