2 * This file is part of FFmpeg.
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.
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.
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
21 * common functions for edge detection
24 #ifndef AVFILTER_EDGE_COMMON_H
25 #define AVFILTER_EDGE_COMMON_H
30 * @brief Rounded directions used in av_image_sobel()
32 enum AVRoundedDirection {
40 * Simple sobel operator to get rounded gradients
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
51 #define PROTO_SOBEL(depth) \
52 void ff_sobel_##depth(int w, int h, \
53 uint16_t *dst, int dst_linesize, \
54 int8_t *dir, int dir_linesize, \
55 const uint8_t *src, int src_linesize, int src_stride);
61 * Filters rounded gradients to drop all non-maxima pixels in the magnitude image
62 * Expects gradients generated by av_image_sobel()
63 * Expects zero's in the destination buffer dst
65 * @param w the width of the image in pixels
66 * @param h the height of the image in pixels
67 * @param dst data pointers to magnitude image
68 * @param dst_linesize linesizes for the magnitude image
69 * @param dir data pointers to direction image
70 * @param dir_linesize linesizes for the direction image
71 * @param src data pointers to source image
72 * @param src_linesize linesizes for the source image
74 void ff_non_maximum_suppression(int w, int h,
75 uint8_t *dst, int dst_linesize,
76 const int8_t *dir, int dir_linesize,
77 const uint16_t *src, int src_linesize);
80 * Filters all pixels in src to keep all pixels > high,
81 * and keep all pixels > low where all surrounding pixels > high
83 * @param low the low threshold value
84 * @param high the hegh threshold value
85 * @param w the width of the image in pixels
86 * @param h the height of the image in pixels
87 * @param dst data pointers to destination image
88 * @param dst_linesize linesizes for the destination image
89 * @param src data pointers to source image
90 * @param src_linesize linesizes for the source image
92 void ff_double_threshold(int low, int high, int w, int h,
93 uint8_t *dst, int dst_linesize,
94 const uint8_t *src, int src_linesize);
97 * Applies gaussian blur.
98 * 5x5 kernels, sigma = 1.4
100 * @param w the width of the image in pixels
101 * @param h the height of the image in pixels
102 * @param dst data pointers to destination image
103 * @param dst_linesize linesizes for the destination image
104 * @param src data pointers to source image
105 * @param src_linesize linesizes for the source image
107 #define PROTO_GAUSSIAN_BLUR(depth) \
108 void ff_gaussian_blur_##depth(int w, int h, \
109 uint8_t *dst, int dst_linesize, \
110 const uint8_t *src, int src_linesize, int src_stride);
112 PROTO_GAUSSIAN_BLUR(8)
113 PROTO_GAUSSIAN_BLUR(16)