blob: 79c4bcc3d1bc7a8fcea424f58e74a243d3d18fd6 [file] [log] [blame]
/*
* Copyright (c) 2012 The WebRTC 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 "webrtc/modules/video_processing/main/source/denoising.h"
#include "webrtc/system_wrappers/interface/trace.h"
#include <string.h>
namespace webrtc {
// Down-sampling in time (unit: number of frames)
enum { kSubsamplingTime = 0 };
// Sub-sampling in width (unit: power of 2.
enum { kSubsamplingWidth = 0 };
// Sub-sampling in height (unit: power of 2)
enum { kSubsamplingHeight = 0 };
// (Q8) De-noising filter parameter
enum { kDenoiseFiltParam = 179 };
// (Q8) 1 - filter parameter
enum { kDenoiseFiltParamRec = 77 };
// (Q8) De-noising threshold level
enum { kDenoiseThreshold = 19200 };
VPMDenoising::VPMDenoising()
: id_(0),
moment1_(NULL),
moment2_(NULL) {
Reset();
}
VPMDenoising::~VPMDenoising() {
if (moment1_) {
delete [] moment1_;
moment1_ = NULL;
}
if (moment2_) {
delete [] moment2_;
moment2_ = NULL;
}
}
int32_t VPMDenoising::ChangeUniqueId(const int32_t id) {
id_ = id;
return VPM_OK;
}
void VPMDenoising::Reset() {
frame_size_ = 0;
denoise_frame_cnt_ = 0;
if (moment1_) {
delete [] moment1_;
moment1_ = NULL;
}
if (moment2_) {
delete [] moment2_;
moment2_ = NULL;
}
}
int32_t VPMDenoising::ProcessFrame(I420VideoFrame* frame) {
assert(frame);
int32_t thevar;
int k;
int jsub, ksub;
int32_t diff0;
uint32_t tmp_moment1;
uint32_t tmp_moment2;
uint32_t tmp;
int32_t num_pixels_changed = 0;
if (frame->IsZeroSize()) {
WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideoPreocessing, id_,
"zero size frame");
return VPM_GENERAL_ERROR;
}
int width = frame->width();
int height = frame->height();
/* Size of luminance component */
const uint32_t y_size = height * width;
/* Initialization */
if (y_size != frame_size_) {
delete [] moment1_;
moment1_ = NULL;
delete [] moment2_;
moment2_ = NULL;
}
frame_size_ = y_size;
if (!moment1_) {
moment1_ = new uint32_t[y_size];
memset(moment1_, 0, sizeof(uint32_t)*y_size);
}
if (!moment2_) {
moment2_ = new uint32_t[y_size];
memset(moment2_, 0, sizeof(uint32_t)*y_size);
}
/* Apply de-noising on each pixel, but update variance sub-sampled */
uint8_t* buffer = frame->buffer(kYPlane);
for (int i = 0; i < height; i++) { // Collect over height
k = i * width;
ksub = ((i >> kSubsamplingHeight) << kSubsamplingHeight) * width;
for (int j = 0; j < width; j++) { // Collect over width
jsub = ((j >> kSubsamplingWidth) << kSubsamplingWidth);
/* Update mean value for every pixel and every frame */
tmp_moment1 = moment1_[k + j];
tmp_moment1 *= kDenoiseFiltParam; // Q16
tmp_moment1 += ((kDenoiseFiltParamRec * ((uint32_t)buffer[k + j])) << 8);
tmp_moment1 >>= 8; // Q8
moment1_[k + j] = tmp_moment1;
tmp_moment2 = moment2_[ksub + jsub];
if ((ksub == k) && (jsub == j) && (denoise_frame_cnt_ == 0)) {
tmp = ((uint32_t)buffer[k + j] *
(uint32_t)buffer[k + j]);
tmp_moment2 *= kDenoiseFiltParam; // Q16
tmp_moment2 += ((kDenoiseFiltParamRec * tmp) << 8);
tmp_moment2 >>= 8; // Q8
}
moment2_[k + j] = tmp_moment2;
/* Current event = deviation from mean value */
diff0 = ((int32_t)buffer[k + j] << 8) - moment1_[k + j];
/* Recent events = variance (variations over time) */
thevar = moment2_[k + j];
thevar -= ((moment1_[k + j] * moment1_[k + j]) >> 8);
// De-noising criteria, i.e., when should we replace a pixel by its mean.
// 1) recent events are minor.
// 2) current events are minor.
if ((thevar < kDenoiseThreshold)
&& ((diff0 * diff0 >> 8) < kDenoiseThreshold)) {
// Replace with mean.
buffer[k + j] = (uint8_t)(moment1_[k + j] >> 8);
num_pixels_changed++;
}
}
}
denoise_frame_cnt_++;
if (denoise_frame_cnt_ > kSubsamplingTime)
denoise_frame_cnt_ = 0;
return num_pixels_changed;
}
} // namespace