1IM_EYE(3) Library Functions Manual IM_EYE(3)
2
3
4
6 im_eye, im_feye - creates a pattern which shows the spatial response of
7 the human visual system
8
10 #include <vips/vips.h>
11
12 int im_eye(image, xsize, ysize, factor)
13 IMAGE *image;
14 int xsize, ysize;
15 double factor;
16
17 int im_feye(image, xsize, ysize, factor)
18 IMAGE *image;
19 int xsize, ysize;
20 double factor;
21
22
24 im_feye() creates an one band float image with pels in [-1,+1] of a
25 pattern which has the following properties:
26 - the spatial frequency increases from left to right.
27 - the grey level intensity decreases from top to bottom.
28 The sizes of the produced image are determined by the entered arguments
29 xsize and ysize. The variable factor which should be between 0 and 1,
30 determines the number of maximum spatial frequencies present along the
31 horizontal direction.
32
33 im_eye() behaves exactly as im_feye(), but scales the output to
34 [0,255].
35
36
38 The function returns 0 on success and -1 on error.
39
41 im_grey(3), im_zone(3).
42
44 N. Dessipris
45
47 N. Dessipris - 10/05/1991
48
49
50
51 10 May 1991 IM_EYE(3)