From 229aaf8d5d4b8b2b12d866f20b798ceb5b8b64d5 Mon Sep 17 00:00:00 2001
From: Jan Philipp Timme <jan.philipp@timme.it>
Date: Thu, 7 Jan 2016 18:45:22 +0100
Subject: [PATCH] [TASK] Parametrize threshold for pixel matchin in hough
 machine.

---
 hough_machine.cpp   | 22 ++++++++++++++++++++--
 imageviewer-qt4.cpp |  4 ++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/hough_machine.cpp b/hough_machine.cpp
index aed2d7d..0b812fa 100644
--- a/hough_machine.cpp
+++ b/hough_machine.cpp
@@ -24,6 +24,8 @@ class HoughMachine {
     int n_rad;
     double d_rad;
     int* hough_arr;
+    
+    int matching_threshold;
 
   public:
     HoughMachine(LazyImage* original, LazyImage* working_copy) {
@@ -47,6 +49,13 @@ class HoughMachine {
 	free(this->hough_arr);
 	this->hough_arr = NULL;
       }
+      this->matching_threshold = 0;
+    };
+    
+    void setMatchingThreshold(int matching_threshold) {
+      // If negative, pixels greater than the absolute value match.
+      // If positive, pixels less than the absolute value match.
+      this->matching_threshold = matching_threshold;
     };
         
     void run(int a_steps, int r_steps) {
@@ -73,8 +82,12 @@ class HoughMachine {
 	  QColor pixel = QColor::fromRgb(this->original->getPixel(u, v, LazyImage::DEFAULT));
 	  int h, s, l;
 	  pixel.getHsl(&h, &s, &l);
-	  if(l < 15) { // TODO: parameterize this
-	    this->doPixel(u, v);
+	  if(this->matching_threshold > 0) {
+	    int threshold = this->matching_threshold;
+	    if(l < threshold) this->doPixel(u, v);
+	  } else {
+	    int threshold = -this->matching_threshold;
+	    if(l > threshold) this->doPixel(u, v);
 	  }
 	}
       }
@@ -92,6 +105,11 @@ class HoughMachine {
       }
     };
     
+    void drawLines(int n) {
+      // TODO: Sort stuff in hough_arr by value, get the n top values and draw them using bresenham.
+      
+    };
+    
     void debugShow() {
       std::cout << "Dimensions: " << this->n_ang << " x " << this->n_rad << " | " << std::endl;
       
diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index e3081f1..79aff10 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -774,7 +774,11 @@ void ImageViewer::runHoughTransformation(void) {
   logFile << "Let's run a hough transformation!" << std::endl;
   renewLogging();
   HoughMachine* hm = new HoughMachine(original, working_copy);
+  hm->setMatchingThreshold(15);
   hm->run(256, 256);
+  
+  hm->drawLines(10);
+  
   delete hm;
   updateImageDisplay();  
 }