| .TH IM_ROTQUAD 3 "07 July 1990" |
| .SH NAME |
| im_rotquad \- rotates the four quadrants of an image |
| .SH SYNOPSIS |
| .B #include <vips/vips.h> |
| |
| .B int im_rotquad(in, out) |
| .br |
| .B IMAGE *in, *out; |
| .SH 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 so-called |
| optical transform. |
| |
| The function operates on any input; |
| output has the same format, sizes and bands as input. |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_fwfft(3), im_invfft(3), im_scaleps(3). |
| .SH COPYRIGHT |
| .br |
| N. Dessipris |
| .SH AUTHOR |
| N. Dessipris \- 06/07/1990 |
