1 * This example program shows how to use saddle_points_sub_pix.
 2 * 
 3 read_image (Image, 'landmarks')
 4 get_image_size (Image, Width, Height)
 5 dev_close_window ()
 6 dev_open_window (0, 0, Width, Height, 'black', WindowHandle)
 7 * 
 8 * saddle_points_sub_pix works only on single channel images. Thus we have
 9 * to convert the input image into a gray value image before using the operator.
10 * 
11 rgb1_to_gray (Image, GrayImage)
12 * 
13 Sigma := 1.5
14 Threshold := 12
15 saddle_points_sub_pix (GrayImage, 'facet', Sigma, Threshold, Row, Col)
16 gen_cross_contour_xld (Crosses, Row, Col, 12, 0.785398)
17 * 
18 dev_display (GrayImage)
19 dev_set_color ('red')
20 dev_display (Crosses)