From 282fa987eda54c1b0f10cf2ecd6ea4f428a3a3fa Mon Sep 17 00:00:00 2001
From: Jan Philipp Timme <jan.philipp@timme.it>
Date: Mon, 23 Nov 2015 13:01:11 +0100
Subject: [PATCH] [!!! TASK] Begin implementing partial linear histogramm
 adaption - broken;

---
 imageviewer-qt4.cpp | 48 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index accf3f0..ddf05d4 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -371,19 +371,53 @@ void ImageViewer::linearHistogrammAdaption(void) {
 void ImageViewer::partialLinearHistogrammAdaption() {
   logFile << "Doing partial linear histogramm adaption ..." << std::endl;
   renewLogging();
-  
-  // TODO
-  
   // Get cumulative histogramm from reference image
+  double* reference_histogramm = histogramm_reference->getRelativeCumulativeIntensityHistogramm();
+  
   // Split [0,255] into n parts (slider)
-  // fetch the values for the n parts, do some math and create the histogramm map
+  int number_parts = partial_adaption_pieces_slider->value();
+  int* parts = (int*) malloc(number_parts*sizeof(int));
+  for(int i=0; i<=number_parts; i++) {
+    parts[i] = qRound((255.0/number_parts)*i);
+  }
+  
+  // Create 
+  double* histogramm_map = (double*) malloc(256*sizeof(double));
+  for(int i=0; i<=number_parts; i++) {
+    int current_n = parts[i];
+    if(current_n == 0) continue; // First part is always at zero!
+    int last_n = parts[i-1];
+    int delta_n = current_n - last_n;
+    double delta_i = reference_histogramm[current_n] - reference_histogramm[last_n];
+    double m = delta_i / delta_n;
+    double offset = histogramm_map[last_n];
+    // Fill in the blanks
+    for(int j=last_n; j<=current_n; j++) {
+      int delta_n = j - last_n;
+      histogramm_map[j] = (offset + delta_n*m);
+      logFile << j << " -> " << histogramm_map[j] << std::endl;
+    }
+  }
   
   // Apply the histogramm map (see succeeding Histogramm Adaption)
-  
-  
-  
+  /*
+  int h, s, l;
+  int pixels = working_copy->getImage()->width() * working_copy->getImage()->height();
+  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 = qRound(histogramm_map[l] * (255/pixels));
+      color.setHsl(h, s, l);
+      working_copy->getImage()->setPixel(x, y, color.rgb());
+    }
+  }*/
+  // Done.
+  free(histogramm_map);
+  free(parts);
   logFile << "done." << std::endl;
   renewLogging();
+  updateImageDisplay();
 }
 
 /**