| .TH IM_ZONE 3 "10 May 1991" |
| .SH NAME |
| im_zone, im_fzone \- creates a zone plate |
| .SH SYNOPSIS |
| .B #include <vips/vips.h> |
| |
| .B int im_zone(image, size) |
| .br |
| .B IMAGE *image; |
| .br |
| .B int size; |
| |
| .B int im_fzone(image, size) |
| .br |
| .B IMAGE *image; |
| .br |
| .B int size; |
| |
| .SH DESCRIPTION |
| |
| .B im_fzone() |
| creates a float one band image of a zone plate of size size by size. Pels are |
| in the range [-1,+1]. The zone plate has spatial frequencies increasing from |
| 0 the center (at size/2, size/2) up to infinity at the edges. size must be |
| positive and even. |
| |
| .B im_zone() |
| behaves exactly as im_fzone(), but writes a FMTUCHAR image scaled to the range |
| 0-255. |
| |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_grey(3), im_fgrey(3). |
| .SH COPYRIGHT |
| N. Dessipris |
| .SH AUTHOR |
| N. Dessipris \- 10/05/1991 |
