[TASK] Implement generic gaussian blur filter.

canny_edge_machine.cpp

@@ -12,14 +12,108 @@
 class CannyEdgeMachine {
   
   private:
-    LazyImage* img;
+    LazyImage* original;
+    LazyImage* working_copy;
+     
+    int width;
+    int height;
+    int pixels;
+    double* gradient_magnitude;
+    double* maximum_magnitude;
+    int* binary_edge_pixels;
+    int* gradient_x;
+    int* gradient_y;
+    
+    // Params
+    double t_low;
+    double t_high;
+    
   public:
-    CannyEdgeMachine(){ 
-      // TODO
+    CannyEdgeMachine(LazyImage* original, LazyImage* working_copy){
+      this->original = original;
+      this->working_copy = working_copy;
+      
+      this->width = this->original->width();
+      this->height = this->original->height();
+      this->pixels = this->width * this->height;
+      
+      this->gradient_magnitude = (double*) malloc(sizeof(double) * this->pixels);
+      this->maximum_magnitude = (double*) malloc(sizeof(double) * this->pixels);
+      this->binary_edge_pixels = (int*) malloc(sizeof(int) * this->pixels);
+      this->gradient_x = (int*) malloc(sizeof(int) * this->pixels);
+      this->gradient_y = (int*) malloc(sizeof(int) * this->pixels);
     };
     
     ~CannyEdgeMachine() {
-      // TODO
+      free(this->gradient_magnitude);
+      free(this->maximum_magnitude);
+      free(this->binary_edge_pixels);
+      free(this->gradient_x);
+      free(this->gradient_y);
+    };
+    
+    void setThresholdValues(double t_low, double t_high) {
+      this->t_low = t_low;
+      this->t_high = t_high;
+    };
+    
+    void reset(void) {
+      for(int i=0; i<this->pixels; i++) {
+	this->gradient_magnitude = 0;
+	this->maximum_magnitude = 0;
+	this->binary_edge_pixels = 0;
+	this->gradient_x = 0;
+	this->gradient_y = 0;
+      }
+    };
+    
+    void doGaussBlur(int filter_width=3) {
+      // build the gauss filter
+      int* filter = (int*) malloc(sizeof(int) * filter_width* filter_width);
+      int sum_weights = 0;
+      for(int i=0; i<filter_width; i++) {
+	for(int j=0; j<filter_width; j++) {
+	  filter[i*filter_width + j] = pow(2, i) * pow(2, j);
+	  sum_weights += filter[i*filter_width + j];
+	}
+      }      
+      // apply gauss filter
+      int filter_offset = (filter_width+1)/2;
+      for(int x=0+filter_offset; x<this->width-filter_offset; x++) {
+        for(int y=0+filter_offset; y<this->width-filter_offset; y++) {
+	  int sum_intensity = 0;
+	  int h, s, l;
+	  for(int fx=0; fx<filter_width; fx++) {
+	    int dx = fx - (filter_width / 2);
+	    for(int fy=0; fy<filter_width; fy++) {
+	      int dy = fy - (filter_width / 2);
+	      QColor color = QColor::fromRgb(this->original->getImage()->pixel(x+dx, y+dy));
+	      color.getHsl(&h, &s, &l);
+	      sum_intensity += (l * filter[fy*filter_width + fx]);
+            }	
+          }
+          QColor color = QColor::fromRgb(original->getImage()->pixel(x, y));
+          color.getHsl(&h, &s, &l);
+          l = qRound((1.0*sum_intensity) / (1.0*sum_weights));
+	  if(l > 255) l = 255;
+	  if(l < 0) l = 0;
+	  color.setHsl(h, s, l);
+	  this->working_copy->getImage()->setPixel(x, y, color.rgb());
+        }
+      }
+      free(filter);
+    };
+    
+    void work() {
+      this->reset();
+      
+      for(int x=0; x<this->width; x++) {
+	for(int y=0; y<this->height; y++) {
+	  //this->gradient_magnitude = sqrt(...)
+	}
+      }
+      
+      
     };
     
 };

imageviewer-qt4.cpp

@@ -650,7 +650,14 @@ void ImageViewer::applyBasicFilterWithOverflowHandling() {
  */
 void ImageViewer::runCannyEdge(void) {
   //TODO
-  CannyEdgeMachine cem = CannyEdgeMachine();
+  
+  // Blur with Gauss (1,2,1 2,4,2 1,2,1) (delta=3, otherwise bigger matrix)
+  
+  // THEN do x/y gradients with (-0.5, 0, 0.5)
+  
+  CannyEdgeMachine cem = CannyEdgeMachine(original, working_copy);
+  cem.setThresholdValues(0, 0); //TODO
+  cem.work();
   
 }
 /**************************************************************************************** 
@@ -917,6 +924,8 @@ void ImageViewer::generateControlPanels() {
   run_canny_edge = new QPushButton("Run canny edge algorithm!");
   QObject::connect(run_canny_edge, SIGNAL(clicked()), this, SLOT(runCannyEdge()));
   
+  task_tab5_scrolllayout->addWidget(run_canny_edge);
+  
   tabWidget->addTab(task_tab5_widget, "Task #5");
   
   //Show it  

lazy_image.cpp

@@ -300,6 +300,13 @@ class LazyImage {
       return result;
     };
     
+    int width(void) {
+      return this->img->width();
+    };
+    
+    int height(void) {
+      return this->img->height();
+    };
 };