1IM_OFFSETS45(3) Library Functions Manual IM_OFFSETS45(3)
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6 im_offsets45, im_offsets90, im_rotate_imask45, im_rotate_dmask45,
7 im_rotate_imask90, im_rotate_dmask90 - rotate square masks
8
10 int *im_offsets45( size )
11 int size;
12 int *im_offsets90( size )
14 int size;
15 INTMASK *im_rotate_imask45( m, name )
17 INTMASK *m;
18 char *name;
19 DOUBLEMASK *im_rotate_dmask45( m, name )
21 DOUBLEMASK *m;
22 char *name;
23 INTMASK *im_rotate_imask90( m, name )
25 INTMASK *m;
26 char *name;
27 DOUBLEMASK *im_rotate_dmask90( m, name )
29 DOUBLEMASK *m;
30 char *name;
31
34 These functions can be used to produce the integer offsets needed to
35 rotate masks by 45 or 90 degrees clockwise.
36 im_offsets45() accepts only even size and returns a pointer to an int
38 buffer of size*size. The program mallocs the buffer and puts into it
39 the integer offsets needed to rotate a mask of even size size by 45
40 degrees. For instance if size is 3 the program returns the buffer 3 0
41 1 6 4 2 7 8 5 which is the offsets needed to rotate a mask with off‐
42 sets 0 1 2 3 4 5 6 7 8. The function return a pointer to valid data
43 on success or NULL on error. Since the program mallocs a buffer, the
44 user should free the returned pointer accordingly.
45 im_offsets90() accepts any size and returns a pointer to an int buffer
47 of size*size. The program mallocs the buffer and puts into it the
48 integer offsets needed to rotate a mask of size size by 90 degrees.
49 For instance if size is 3 the program returns the buffer 6 3 0 7 4 1
50 8 5 2 which is the offsets needed to rotate a mask with offsets 0 1 2
51 3 4 5 6 7 8. The function return a pointers to valid data on success
52 or NULL on error. Since the program mallocs a buffer, the user should
53 free the returned pointer accordingly.
54 im_rotate_imask45() rotates the INTMASK m by 45 degrees and returns the
56 rotated mask. The filename member of the returned structure is set to
57 name. The program allocates memory for the new mask and therefore the
58 user must free the returned mask by a call to im_free_imask(3). The
59 returned mask is rotated by 45 degrees clockwise. The function return
60 a valid INTMASK pointer on success or NULL on error.
61 im_rotate_dmask45() rotates the DOUBLEMASK m by 45 degrees and returns
63 the rotated mask. The filename member of the returned structure is set
64 to name. The program allocates memory for the new mask and therefore
65 the user must free the returned mask by a call to im_free_dmask(3).
66 The returned mask is rotated by 45 degrees clockwise. The function
67 return a valid DOUBLEMASK pointer on success or NULL on error.
68 im_rotate_imask90() rotates the INTMASK m by 90 degrees and returns the
70 rotated mask. The filename member of the returned structure is set to
71 name. The program allocates memory for the new mask and therefore the
72 user must free the returned mask by a call to im_free_imask(3). The
73 returned mask is rotated by 90 degrees clockwise. The function return
74 a valid INTMASK pointer on success or NULL on error.
75 im_rotate_dmask90() rotates the DOUBLEMASK m by 90 degrees and returns
77 the rotated mask. The filename member of the returned structure is set
78 to name. The program allocates memory for the new mask and therefore
79 the user must free the returned mask by a call to im_free_dmask(3).
80 The returned mask is rotated by 90 degrees clockwise. The function
81 return a valid DOUBLEMASK pointer on success or NULL on error.
82
86 im_read_imask(3), im_read_dmask(3), im_free_imask(3), im_free_dmask(3),
87 im_gradient(3), im_compass(3), im_conv(3).
88
90 N. Dessipris
91
93 N. Dessipris -28/05/1991
94 28 May 1991 IM_OFFSETS45(3)