1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 /**
20 * @file
21 * common functions for edge detection
22 */
23
24 #ifndef AVFILTER_EDGE_COMMON_H
25 #define AVFILTER_EDGE_COMMON_H
26
28
29 /**
30 * @brief Rounded directions used in av_image_sobel()
31 */
37 };
38
39 /**
40 * Simple sobel operator to get rounded gradients
41 *
42 * @param w the width of the image in pixels
43 * @param h the height of the image in pixels
44 * @param dst data pointers to magnitude image
45 * @param dst_linesize linesizes for the magnitude image
46 * @param dir data pointers to direction image
47 * @param dir_linesize linesizes for the direction image
48 * @param src data pointers to source image
49 * @param src_linesize linesizes for the source image
50 */
52 uint16_t *dst, int dst_linesize,
53 int8_t *dir, int dir_linesize,
54 const uint8_t *
src,
int src_linesize);
55
56 /**
57 * Filters rounded gradients to drop all non-maxima pixels in the magnitude image
58 * Expects gradients generated by av_image_sobel()
59 * Expects zero's in the destination buffer dst
60 *
61 * @param w the width of the image in pixels
62 * @param h the height of the image in pixels
63 * @param dst data pointers to magnitude image
64 * @param dst_linesize linesizes for the magnitude image
65 * @param dir data pointers to direction image
66 * @param dir_linesize linesizes for the direction image
67 * @param src data pointers to source image
68 * @param src_linesize linesizes for the source image
69 */
71 uint8_t *dst, int dst_linesize,
72 const int8_t *dir, int dir_linesize,
73 const uint16_t *
src,
int src_linesize);
74
75 /**
76 * Filters all pixels in src to keep all pixels > high,
77 * and keep all pixels > low where all surrounding pixels > high
78 *
79 * @param low the low threshold value
80 * @param high the hegh threshold value
81 * @param w the width of the image in pixels
82 * @param h the height of the image in pixels
83 * @param dst data pointers to destination image
84 * @param dst_linesize linesizes for the destination image
85 * @param src data pointers to source image
86 * @param src_linesize linesizes for the source image
87 */
89 uint8_t *dst, int dst_linesize,
90 const uint8_t *
src,
int src_linesize);
91
92 /**
93 * Applies gaussian blur.
94 * 5x5 kernels, sigma = 1.4
95 *
96 * @param w the width of the image in pixels
97 * @param h the height of the image in pixels
98 * @param dst data pointers to destination image
99 * @param dst_linesize linesizes for the destination image
100 * @param src data pointers to source image
101 * @param src_linesize linesizes for the source image
102 */
104 uint8_t *dst, int dst_linesize,
105 const uint8_t *
src,
int src_linesize);
106
107 #endif