From b335af67aa5ab4e478aa0749a7ccc0561d435707 Mon Sep 17 00:00:00 2001
From: Nicolas Pope <nwpope@utu.fi>
Date: Sat, 22 Jun 2019 18:35:23 +0300
Subject: [PATCH] Add gamma and temperature to snapshot source
---
.../rgbd-sources/src/snapshot_source.cpp | 73 +++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/components/rgbd-sources/src/snapshot_source.cpp b/components/rgbd-sources/src/snapshot_source.cpp
index 367fc2861..59bd31aa4 100644
--- a/components/rgbd-sources/src/snapshot_source.cpp
+++ b/components/rgbd-sources/src/snapshot_source.cpp
@@ -1,16 +1,89 @@
#include "snapshot_source.hpp"
+#include <loguru.hpp>
#include <opencv2/opencv.hpp>
#include <Eigen/Eigen>
#include <opencv2/core/eigen.hpp>
+#include <vector>
using namespace ftl::rgbd;
using ftl::rgbd::detail::SnapshotSource;
using std::string;
+using std::vector;
+
+static void gammaCorrection(const cv::Mat &img, const double gamma_){
+ using namespace cv;
+
+ Mat lookUpTable(1, 256, CV_8U);
+ uchar* p = lookUpTable.ptr();
+ for( int i = 0; i < 256; ++i)
+ p[i] = saturate_cast<uchar>(pow(i / 255.0, gamma_) * 255.0);
+
+ Mat res = img.clone();
+ LUT(img, lookUpTable, img);
+}
+
+static const std::vector<std::tuple<uchar,uchar,uchar>> kelvin_table = {
+ {255,56,0}, // 1000
+ {255,109,0}, // 1500
+ {255,137,18}, // 2000
+ {255,161,72}, // 2500
+ {255,180,107}, // 3000
+ {255,196,137}, // 3500
+ {255,209,163}, // 4000
+ {255,219,186}, // 4500
+ {255,228,206}, // 5000
+ {255,236,224}, // 5500
+ {255,243,239}, // 6000
+ {255,249,253}, // 6500
+ {245,243,255}, // 7000
+ {235,238,255}, // 7500
+ {227,233,255}, // 8000
+ {220,229,255}, // 8500
+ {214,225,255}, // 9000
+ {208,222,255}, // 9500
+ {204,219,255}}; // 10000
+
+template <int C>
+inline float kelvinFactor(int temp) {
+ int index = (temp / 500) - 2;
+ if (index >= kelvin_table.size()) index = kelvin_table.size();
+ else if (index < 0) index = 0;
+ return (float)std::get<C>(kelvin_table[index]) / 255.0f;
+}
+
+static void colourCorrection(cv::Mat &img, float gamma, int temp) {
+ using namespace cv;
+
+ Mat lutRed(1, 256, CV_8U);
+ Mat lutGreen(1, 256, CV_8U);
+ Mat lutBlue(1, 256, CV_8U);
+
+ // TODO(Nick): Cache these lookup tables if used every frame...
+ uchar* pr = lutRed.ptr();
+ uchar* pg = lutGreen.ptr();
+ uchar* pb = lutBlue.ptr();
+ for( int i = 0; i < 256; ++i) {
+ float g = pow(i / 255.0f, gamma) * 255.0f;
+ pr[i] = saturate_cast<uchar>(g * kelvinFactor<2>(temp));
+ pg[i] = saturate_cast<uchar>(g * kelvinFactor<1>(temp));
+ pb[i] = saturate_cast<uchar>(g * kelvinFactor<0>(temp));
+ }
+
+ vector<Mat> channels(3);
+ split(img, channels);
+ LUT(channels[0], lutBlue, channels[0]);
+ LUT(channels[1], lutGreen, channels[1]);
+ LUT(channels[2], lutRed, channels[2]);
+ merge(channels, img);
+}
SnapshotSource::SnapshotSource(ftl::rgbd::Source *host, SnapshotReader &reader, const string &id) : detail::Source(host) {
Eigen::Matrix4d pose;
reader.getCameraRGBD(id, rgb_, depth_, pose, params_);
+
+ colourCorrection(rgb_, host->value("gamma", 2.2f), host->value("temperature", 6500));
+
setPose(pose);
}
--
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