IM_ROTQUAD(3)

NAME

im_rotquad - rotates the four quadrants of an image

SYNOPSIS

#include <vips/vips.h>

int im_rotquad(in, out)
IMAGE *in, *out;

DESCRIPTION

im_rotquad rotates the four quadrants of the image held by the image descriptor in and writes the result on the image descriptor out.

The function is used primarily to rotate a fourier transform in such a way that the coordinate (0,0) is near the centre of the image, the socalled optical transform.

The function operates on any input; output has the same format, sizes and bands as input.

RETURN VALUE

The function returns 0 on success and -1 on error.

SEE ALSO

im_fwfft(3), im_invfft(3), im_scaleps(3).

COPYRIGHT

N. Dessipris

AUTHOR

N. Dessipris - 06/07/1990

07 July 1990 IM_ROTQUAD(3)