From c0ed0711905b36ea63c907d4664fb133c128aba6 Mon Sep 17 00:00:00 2001
From: Jan Philipp Timme <jan.philipp@timme.it>
Date: Fri, 20 Nov 2015 13:31:27 +0100
Subject: [PATCH] [TASK] Almost finish piecebased histogramm adaption.

---
 imageviewer-qt4.cpp | 59 ++++++++++++++++++++++++++++++++++++++++++++-
 imageviewer-qt4.h   |  2 ++
 lazy_image.cpp      |  8 ++++++
 3 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index ab854ad..176b0c4 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -363,6 +363,59 @@ void ImageViewer::linearHistogrammAdaption(void) {
   renewLogging();
 }
 
+/**
+ * Do a piece based linear histogramm adaption using a reference image.
+ * 
+ * @brief Imageviewer::pieceLinearHistogrammAdaption
+ */
+void ImageViewer::pieceLinearHistogrammAdaption() {
+  logFile << "Doing linear histogramm adaption ..." << std::endl;
+  renewLogging();
+  if(histogramm_reference == NULL) {
+    logFile << "No reference image loaded! Aborting." << std::endl;
+    renewLogging();
+    return;
+  } else {
+    // Create an intensity map
+    int histogramm_map[256];
+    for(int i=0; i<256; i++) histogramm_map[i] = -1;
+    int source_cursor = 0;
+    double used_space = 0.0;
+    double* source_histogramm = working_copy->getRelativeIntensityHistogramm();
+    double* target_cummulative_histogramm = histogramm_reference->getRelativeCumulativeIntensityHistogramm();
+    for(int i=0; i<256; i++) {
+      double free_total_space = target_cummulative_histogramm[i];
+      while(source_histogramm[source_cursor] <= (free_total_space - used_space)) {
+	histogramm_map[source_cursor] = i;
+	used_space += source_histogramm[source_cursor];
+	source_cursor++;
+      }
+    }
+    
+    for(int i=0; i<256; i++) {
+      logFile << i << ": " << histogramm_map[i] << std::endl;
+    }
+    renewLogging();
+    
+    // Apply the map for each pixel.
+    int h, s, l;
+    for(int x=0; x<working_copy->getImage()->width(); x++) {
+      for(int y=0; y<working_copy->getImage()->height(); y++) {
+	QColor color = QColor::fromRgb(original->getImage()->pixel(x, y));
+	color.getHsl(&h, &s, &l);
+        l = histogramm_map[l];
+        color.setHsl(h, s, l);
+        working_copy->getImage()->setPixel(x, y, color.rgb());
+      }
+    }
+    // Done.
+  }
+  logFile << "done." << std::endl;
+  renewLogging();
+  updateImageDisplay();
+}
+
+
 
 /**************************************************************************************** 
 *   
@@ -511,7 +564,10 @@ void ImageViewer::generateControlPanels() {
 
   linear_histogramm_adaption = new QPushButton("Do linear histogramm adaption (basic)");
   QObject::connect(linear_histogramm_adaption, SIGNAL(clicked()), this, SLOT(linearHistogrammAdaption()));
-   
+
+  piece_linear_histogramm_adaption = new QPushButton("Do linear histogramm adaption (pieces)");
+  QObject::connect(piece_linear_histogramm_adaption, SIGNAL(clicked()), this, SLOT(pieceLinearHistogrammAdaption()));
+
   task_tab3->addWidget(new QLabel("Reference image"));
   task_tab3->addWidget(reference_histogramm_cumulative_label);
   task_tab3->addWidget(new QLabel("Original image"));
@@ -519,6 +575,7 @@ void ImageViewer::generateControlPanels() {
   task_tab3->addWidget(new QLabel("Working copy"));
   task_tab3->addWidget(histogramm_cumulative_label);
   task_tab3->addWidget(linear_histogramm_adaption);
+  task_tab3->addWidget(piece_linear_histogramm_adaption);
   
   tabWidget->addTab(task_tab_widget3, "Task #3");
   
diff --git a/imageviewer-qt4.h b/imageviewer-qt4.h
index 3c49e95..c658703 100644
--- a/imageviewer-qt4.h
+++ b/imageviewer-qt4.h
@@ -110,6 +110,7 @@ class ImageViewer : public QMainWindow {
     QLabel* histogramm_cumulative_label;
     
     QPushButton* linear_histogramm_adaption;
+    QPushButton* piece_linear_histogramm_adaption;
     
     // "My" space for storing data/results
     LazyImage* original;
@@ -129,6 +130,7 @@ class ImageViewer : public QMainWindow {
     void saveToOriginal();
     void robustAutomaticContrastAdaption(int c_param);
     void linearHistogrammAdaption();
+    void pieceLinearHistogrammAdaption();
 
     void open();
     void openReference();
diff --git a/lazy_image.cpp b/lazy_image.cpp
index 503b208..8e9a195 100644
--- a/lazy_image.cpp
+++ b/lazy_image.cpp
@@ -16,6 +16,7 @@ class LazyImage {
     QImage* histogramm_normal_image;
     QImage* histogramm_cumulative_image;
     double histogramm_relative_intensity[256];
+    double histogramm_relative_cumulative_intensity[256];
     int histogramm_absolute_intensity[256];
     int histogramm_absolute_cumulative_intensity[256];
     int intensity_average;
@@ -42,10 +43,13 @@ class LazyImage {
       // Calculate relative histogramm and absolute cumulative histogramm
       int pixels = this->img->width()*this->img->height();
       int sum = 0;
+      double relative_sum = 0.0;
       for(int i=0; i<256; i++) {
 	histogramm_relative_intensity[i] = (((double) histogramm_absolute_intensity[i])/((double) pixels));
 	sum += histogramm_absolute_intensity[i];
+	relative_sum += histogramm_relative_intensity[i];
 	histogramm_absolute_cumulative_intensity[i] = sum;
+	histogramm_relative_cumulative_intensity[i] = relative_sum;
       }
     };
     
@@ -181,6 +185,10 @@ class LazyImage {
       return this->histogramm_relative_intensity;
     };
     
+    double* getRelativeCumulativeIntensityHistogramm(void) {
+      return this->histogramm_relative_cumulative_intensity;
+    };
+    
     void convertToMonochrome(void) {
       for(int x=0; x<this->img->width(); x++) {
         for(int y=0; y<this->img->height(); y++) {