**Name**

**fsym2** Symmetrize a Fimage in both directions

**Command Synopsis**

**fsym2** [-i] *in* *out*

-i : inverse (extract upleft corner)

in: input Fimage

out: output Fimage

**Function Summary**

void fsym2 (in , out , i )

Fimage in , out ;

char *i ;

**Description**

This module performs a double (x and y axes) symmetrization of an image.
It allows to avoid boundary effects
when computing the Fourier Transform of an image, since such
a symmetrization followed by a Fourier Transform is equivalent to
a Cosine Transform of the original image.
The `-i`

option performs the inverse operation (extraction of
the upleft corner).

**See Also**

**Version 1.0**

Last Modification date : Thu Nov 29 20:23:56 2001

**Author**

Lionel Moisan