| /* |
| * Copyright (c) 2011 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/brightness_detection.h" |
| |
| #include <math.h> |
| |
| #include "webrtc/modules/video_processing/include/video_processing.h" |
| |
| namespace webrtc { |
| |
| VPMBrightnessDetection::VPMBrightnessDetection() { |
| Reset(); |
| } |
| |
| VPMBrightnessDetection::~VPMBrightnessDetection() {} |
| |
| void VPMBrightnessDetection::Reset() { |
| frame_cnt_bright_ = 0; |
| frame_cnt_dark_ = 0; |
| } |
| |
| int32_t VPMBrightnessDetection::ProcessFrame( |
| const VideoFrame& frame, |
| const VideoProcessing::FrameStats& stats) { |
| if (frame.IsZeroSize()) { |
| return VPM_PARAMETER_ERROR; |
| } |
| int width = frame.width(); |
| int height = frame.height(); |
| |
| if (!VideoProcessing::ValidFrameStats(stats)) { |
| return VPM_PARAMETER_ERROR; |
| } |
| |
| const uint8_t frame_cnt_alarm = 2; |
| |
| // Get proportion in lowest bins. |
| uint8_t low_th = 20; |
| float prop_low = 0; |
| for (uint32_t i = 0; i < low_th; i++) { |
| prop_low += stats.hist[i]; |
| } |
| prop_low /= stats.num_pixels; |
| |
| // Get proportion in highest bins. |
| unsigned char high_th = 230; |
| float prop_high = 0; |
| for (uint32_t i = high_th; i < 256; i++) { |
| prop_high += stats.hist[i]; |
| } |
| prop_high /= stats.num_pixels; |
| |
| if (prop_high < 0.4) { |
| if (stats.mean < 90 || stats.mean > 170) { |
| // Standard deviation of Y |
| const uint8_t* buffer = frame.buffer(kYPlane); |
| float std_y = 0; |
| for (int h = 0; h < height; h += (1 << stats.sub_sampling_factor)) { |
| int row = h * width; |
| for (int w = 0; w < width; w += (1 << stats.sub_sampling_factor)) { |
| std_y += |
| (buffer[w + row] - stats.mean) * (buffer[w + row] - stats.mean); |
| } |
| } |
| std_y = sqrt(std_y / stats.num_pixels); |
| |
| // Get percentiles. |
| uint32_t sum = 0; |
| uint32_t median_y = 140; |
| uint32_t perc05 = 0; |
| uint32_t perc95 = 255; |
| float pos_perc05 = stats.num_pixels * 0.05f; |
| float pos_median = stats.num_pixels * 0.5f; |
| float posPerc95 = stats.num_pixels * 0.95f; |
| for (uint32_t i = 0; i < 256; i++) { |
| sum += stats.hist[i]; |
| if (sum < pos_perc05) |
| perc05 = i; // 5th perc. |
| if (sum < pos_median) |
| median_y = i; // 50th perc. |
| if (sum < posPerc95) |
| perc95 = i; // 95th perc. |
| else |
| break; |
| } |
| |
| // Check if image is too dark |
| if ((std_y < 55) && (perc05 < 50)) { |
| if (median_y < 60 || stats.mean < 80 || perc95 < 130 || |
| prop_low > 0.20) { |
| frame_cnt_dark_++; |
| } else { |
| frame_cnt_dark_ = 0; |
| } |
| } else { |
| frame_cnt_dark_ = 0; |
| } |
| |
| // Check if image is too bright |
| if ((std_y < 52) && (perc95 > 200) && (median_y > 160)) { |
| if (median_y > 185 || stats.mean > 185 || perc05 > 140 || |
| prop_high > 0.25) { |
| frame_cnt_bright_++; |
| } else { |
| frame_cnt_bright_ = 0; |
| } |
| } else { |
| frame_cnt_bright_ = 0; |
| } |
| } else { |
| frame_cnt_dark_ = 0; |
| frame_cnt_bright_ = 0; |
| } |
| } else { |
| frame_cnt_bright_++; |
| frame_cnt_dark_ = 0; |
| } |
| |
| if (frame_cnt_dark_ > frame_cnt_alarm) { |
| return VideoProcessing::kDarkWarning; |
| } else if (frame_cnt_bright_ > frame_cnt_alarm) { |
| return VideoProcessing::kBrightWarning; |
| } else { |
| return VideoProcessing::kNoWarning; |
| } |
| } |
| |
| } // namespace webrtc |