lafi/vf_edgedetect: Move some common functions into seperate file

1 files changed, 107 insertions, 0 deletions

diff --git a/libavfilter/edge_common.h b/libavfilter/edge_common.h
new file mode 100644
index 0000000000..87c143f2b8
--- /dev/null
+++ b/libavfilter/edge_common.h
@@ -0,0 +1,107 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * common functions for edge detection
+ */
+
+#ifndef AVFILTER_EDGE_COMMON_H
+#define AVFILTER_EDGE_COMMON_H
+
+#include "avfilter.h"
+
+/**
+ * @brief Rounded directions used in av_image_sobel()
+ */
+enum AVRoundedDirection {
+    DIRECTION_45UP,
+    DIRECTION_45DOWN,
+    DIRECTION_HORIZONTAL,
+    DIRECTION_VERTICAL,
+};
+
+/**
+ * Simple sobel operator to get rounded gradients
+ *
+ * @param w             the width of the image in pixels
+ * @param h             the height of the image in pixels
+ * @param dst           data pointers to magnitude image
+ * @param dst_linesize  linesizes for the magnitude image
+ * @param dir           data pointers to direction image
+ * @param dir_linesize  linesizes for the direction image
+ * @param src           data pointers to source image
+ * @param src_linesize  linesizes for the source image
+ */
+void ff_sobel(int w, int h,
+              uint16_t *dst, int dst_linesize,
+              int8_t *dir, int dir_linesize,
+              const uint8_t *src, int src_linesize);
+
+/**
+ * Filters rounded gradients to drop all non-maxima pixels in the magnitude image
+ * Expects gradients generated by av_image_sobel()
+ * Expects zero's in the destination buffer dst
+ *
+ * @param w             the width of the image in pixels
+ * @param h             the height of the image in pixels
+ * @param dst           data pointers to magnitude image
+ * @param dst_linesize  linesizes for the magnitude image
+ * @param dir           data pointers to direction image
+ * @param dir_linesize  linesizes for the direction image
+ * @param src           data pointers to source image
+ * @param src_linesize  linesizes for the source image
+ */
+void ff_non_maximum_suppression(int w, int h,
+                                uint8_t *dst, int dst_linesize,
+                                const int8_t *dir, int dir_linesize,
+                                const uint16_t *src, int src_linesize);
+
+/**
+ * Filters all pixels in src to keep all pixels > high,
+ * and keep all pixels > low where all surrounding pixels > high
+ *
+ * @param low           the low threshold value
+ * @param high          the hegh threshold value
+ * @param w             the width of the image in pixels
+ * @param h             the height of the image in pixels
+ * @param dst           data pointers to destination image
+ * @param dst_linesize  linesizes for the destination image
+ * @param src           data pointers to source image
+ * @param src_linesize  linesizes for the source image
+ */
+void ff_double_threshold(int low, int high, int w, int h,
+                         uint8_t *dst, int dst_linesize,
+                         const uint8_t *src, int src_linesize);
+
+/**
+ * Applies gaussian blur.
+ * 5x5 kernels, sigma = 1.4
+ *
+ * @param w             the width of the image in pixels
+ * @param h             the height of the image in pixels
+ * @param dst           data pointers to destination image
+ * @param dst_linesize  linesizes for the destination image
+ * @param src           data pointers to source image
+ * @param src_linesize  linesizes for the source image
+ */
+void ff_gaussian_blur(int w, int h,
+                      uint8_t *dst, int dst_linesize,
+                      const uint8_t *src, int src_linesize);
+
+#endif