ref: cc7d981de158853c3ea87fe15eb3c43ba7b58e99
parent: f4c29ae9ea16c502c980a81ca9683327d5051929
parent: 56435bb7b6ed888572c8a20ce873e95afd9f1ee9
author: Marco <marpan@google.com>
date: Thu Feb 12 06:12:27 EST 2015
Merge "Add skin detection."
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -50,6 +50,7 @@
#include "vp9/encoder/vp9_temporal_filter.h"
#include "vp9/encoder/vp9_resize.h"
#include "vp9/encoder/vp9_svc_layercontext.h"
+#include "vp9/encoder/vp9_skin_detection.h"
#define SHARP_FILTER_QTHRESH 0 /* Q threshold for 8-tap sharp filter */
@@ -60,12 +61,14 @@
// mv. Choose a very high value for
// now so that HIGH_PRECISION is always
// chosen.
-
// #define OUTPUT_YUV_REC
#ifdef OUTPUT_YUV_DENOISED
FILE *yuv_denoised_file = NULL;
#endif
+#ifdef OUTPUT_YUV_SKINMAP
+FILE *yuv_skinmap_file = NULL;
+#endif
#ifdef OUTPUT_YUV_REC
FILE *yuv_rec_file;
#endif
@@ -1541,6 +1544,9 @@
yuv_denoised_file = fopen("denoised.yuv", "ab");#endif
#endif
+#ifdef OUTPUT_YUV_SKINMAP
+ yuv_skinmap_file = fopen("skinmap.yuv", "ab");+#endif
#ifdef OUTPUT_YUV_REC
yuv_rec_file = fopen("rec.yuv", "wb");#endif
@@ -1829,6 +1835,9 @@
fclose(yuv_denoised_file);
#endif
#endif
+#ifdef OUTPUT_YUV_SKINMAP
+ fclose(yuv_skinmap_file);
+#endif
#ifdef OUTPUT_YUV_REC
fclose(yuv_rec_file);
#endif
@@ -2116,8 +2125,7 @@
return 0;
}
-#if CONFIG_VP9_TEMPORAL_DENOISING
-#if defined(OUTPUT_YUV_DENOISED)
+#if defined(OUTPUT_YUV_DENOISED) || defined(OUTPUT_YUV_SKINMAP)
// The denoiser buffer is allocated as a YUV 440 buffer. This function writes it
// as YUV 420. We simply use the top-left pixels of the UV buffers, since we do
// not denoise the UV channels at this time. If ever we implement UV channel
@@ -2148,7 +2156,6 @@
} while (--h);
}
#endif
-#endif
#ifdef OUTPUT_YUV_REC
void vp9_write_yuv_rec_frame(VP9_COMMON *cm) {@@ -3299,7 +3306,11 @@
}
#endif
#endif
-
+#ifdef OUTPUT_YUV_SKINMAP
+ if (cpi->common.current_video_frame > 1) {+ vp9_compute_skin_map(cpi, yuv_skinmap_file);
+ }
+#endif
// Special case code to reduce pulsing when key frames are forced at a
// fixed interval. Note the reconstruction error if it is the frame before
--- /dev/null
+++ b/vp9/encoder/vp9_skin_detection.c
@@ -1,0 +1,104 @@
+/*
+ * Copyright (c) 2015 The WebM project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <limits.h>
+#include <math.h>
+
+#include "vp9/common/vp9_blockd.h"
+#include "vp9/encoder/vp9_encoder.h"
+#include "vp9/encoder/vp9_skin_detection.h"
+
+// Fixed-point skin color model parameters.
+static const int skin_mean[2] = {7463, 9614}; // q6+static const int skin_inv_cov[4] = {4107, 1663, 1663, 2157}; // q16+static const int skin_threshold = 1570636; // q18
+
+// Thresholds on luminance.
+static const int y_low = 20;
+static const int y_high = 220;
+
+// Evaluates the Mahalanobis distance measure for the input CbCr values.
+static int evaluate_skin_color_difference(int cb, int cr) {+ const int cb_q6 = cb << 6;
+ const int cr_q6 = cr << 6;
+ const int cb_diff_q12 = (cb_q6 - skin_mean[0]) * (cb_q6 - skin_mean[0]);
+ const int cbcr_diff_q12 = (cb_q6 - skin_mean[0]) * (cr_q6 - skin_mean[1]);
+ const int cr_diff_q12 = (cr_q6 - skin_mean[1]) * (cr_q6 - skin_mean[1]);
+ const int cb_diff_q2 = (cb_diff_q12 + (1 << 9)) >> 10;
+ const int cbcr_diff_q2 = (cbcr_diff_q12 + (1 << 9)) >> 10;
+ const int cr_diff_q2 = (cr_diff_q12 + (1 << 9)) >> 10;
+ const int skin_diff = skin_inv_cov[0] * cb_diff_q2 +
+ skin_inv_cov[1] * cbcr_diff_q2 +
+ skin_inv_cov[2] * cbcr_diff_q2 +
+ skin_inv_cov[3] * cr_diff_q2;
+ return skin_diff;
+}
+
+int vp9_skin_pixel(const uint8_t y, const uint8_t cb, const uint8_t cr) {+ if (y < y_low || y > y_high)
+ return 0;
+ else
+ return (evaluate_skin_color_difference(cb, cr) < skin_threshold);
+}
+
+#ifdef OUTPUT_YUV_SKINMAP
+// For viewing skin map on input source.
+void vp9_compute_skin_map(VP9_COMP *const cpi, FILE *yuv_skinmap_file) {+ int i, j, mi_row, mi_col;
+ VP9_COMMON *const cm = &cpi->common;
+ uint8_t *y;
+ const uint8_t *src_y = cpi->Source->y_buffer;
+ const uint8_t *src_u = cpi->Source->u_buffer;
+ const uint8_t *src_v = cpi->Source->v_buffer;
+ const int src_ystride = cpi->Source->y_stride;
+ const int src_uvstride = cpi->Source->uv_stride;
+ YV12_BUFFER_CONFIG skinmap;
+ vpx_memset(&skinmap, 0, sizeof(YV12_BUFFER_CONFIG));
+ if (vp9_alloc_frame_buffer(&skinmap, cm->width, cm->height,
+ cm->subsampling_x, cm->subsampling_y,
+ VP9_ENC_BORDER_IN_PIXELS, cm->byte_alignment)) {+ vp9_free_frame_buffer(&skinmap);
+ return;
+ }
+ vpx_memset(skinmap.buffer_alloc, 128, skinmap.frame_size);
+ y = skinmap.y_buffer;
+ // Loop through 8x8 blocks and set skin map based on center pixel of block.
+ // Set y to white for skin block, otherwise set to source with gray scale.
+ // Ignore rightmost/bottom boundary blocks.
+ for (mi_row = 0; mi_row < cm->mi_rows - 1; ++mi_row) {+ for (mi_col = 0; mi_col < cm->mi_cols - 1; ++mi_col) {+ // Use middle pixel for each 8x8 block for skin detection.
+ // If middle pixel is skin, assign whole 8x8 block to skin.
+ const uint8_t ysource = src_y[4 * src_ystride + 4];
+ const uint8_t usource = src_u[2 * src_uvstride + 2];
+ const uint8_t vsource = src_v[2 * src_uvstride + 2];
+ const int is_skin = vp9_skin_pixel(ysource, usource, vsource);
+ for (i = 0; i < 8; i++) {+ for (j = 0; j < 8; j++) {+ if (is_skin)
+ y[i * src_ystride + j] = 255;
+ else
+ y[i * src_ystride + j] = src_y[i * src_ystride + j];
+ }
+ }
+ y += 8;
+ src_y += 8;
+ src_u += 4;
+ src_v += 4;
+ }
+ y += (src_ystride << 3) - ((cm->mi_cols - 1) << 3);
+ src_y += (src_ystride << 3) - ((cm->mi_cols - 1) << 3);
+ src_u += (src_uvstride << 2) - ((cm->mi_cols - 1) << 2);
+ src_v += (src_uvstride << 2) - ((cm->mi_cols - 1) << 2);
+ }
+ vp9_write_yuv_frame_420(&skinmap, yuv_skinmap_file);
+ vp9_free_frame_buffer(&skinmap);
+}
+#endif
--- /dev/null
+++ b/vp9/encoder/vp9_skin_detection.h
@@ -1,0 +1,35 @@
+/*
+ * Copyright (c) 2015 The WebM project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VP9_ENCODER_VP9_SKIN_MAP_H_
+#define VP9_ENCODER_VP9_SKIN_MAP_H_
+
+#include "vp9/common/vp9_blockd.h"
+
+#ifdef __cplusplus
+extern "C" {+#endif
+
+struct VP9_COMP;
+
+// #define OUTPUT_YUV_SKINMAP
+
+int vp9_skin_pixel(const uint8_t y, const uint8_t cb, const uint8_t cr);
+
+#ifdef OUTPUT_YUV_SKINMAP
+// For viewing skin map on input source.
+void vp9_compute_skin_map(VP9_COMP *const cpi, FILE *yuv_skinmap_file);
+#endif
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // VP9_ENCODER_VP9_SKIN_MAP_H_
--- a/vp9/vp9cx.mk
+++ b/vp9/vp9cx.mk
@@ -88,6 +88,8 @@
VP9_CX_SRCS-yes += encoder/vp9_aq_cyclicrefresh.h
VP9_CX_SRCS-yes += encoder/vp9_aq_complexity.c
VP9_CX_SRCS-yes += encoder/vp9_aq_complexity.h
+VP9_CX_SRCS-yes += encoder/vp9_skin_detection.c
+VP9_CX_SRCS-yes += encoder/vp9_skin_detection.h
ifeq ($(CONFIG_VP9_POSTPROC),yes)
VP9_CX_SRCS-$(CONFIG_INTERNAL_STATS) += common/vp9_postproc.h
VP9_CX_SRCS-$(CONFIG_INTERNAL_STATS) += common/vp9_postproc.c