int im_rotquad(in, out)
IMAGE *in, *out;
DESCRIPTIONim_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 so-called optical transform.
The function operates on any input; output has the same format, sizes and bands as input.
RETURN VALUEThe function returns 0 on success and -1 on error.
AUTHORN. Dessipris - 06/07/1990