diff --git a/canny_edge_machine.cpp b/canny_edge_machine.cpp
index 19f6c37..ccfbd59 100644
--- a/canny_edge_machine.cpp
+++ b/canny_edge_machine.cpp
@@ -244,6 +244,21 @@ class CannyEdgeMachine {
       }
     };
     
+    void showEdges(void) {
+      QRgb black = QColor::fromRgb(0, 0, 0).rgb();
+      QRgb white = QColor::fromRgb(255, 255, 255).rgb();
+      for(int x=0; x<this->width; x++) {
+	for(int y=0; y<this->height; y++) {
+	  int pixel = this->binary_edge_pixels[y*this->width + x];
+	  if(pixel > 0) {
+	    this->working_copy->getImage()->setPixel(x, y, white);
+	  } else {
+	    this->working_copy->getImage()->setPixel(x, y, black);
+	  }
+	}
+      }
+    };
+    
     void work() {
       this->reset();
       this->doGaussBlur();
@@ -251,6 +266,7 @@ class CannyEdgeMachine {
       this->doGradiantMagnitude();
       this->filterLocalMaxima();
       this->workLocalMaxima();
+      this->showEdges();
     };
     
 };
diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index ee96fb9..b903564 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -651,7 +651,7 @@ void ImageViewer::applyBasicFilterWithOverflowHandling() {
 void ImageViewer::runCannyEdge(void) {
   //TODO
   CannyEdgeMachine cem = CannyEdgeMachine(original, working_copy);
-  cem.setThresholdValues(0, 0); //TODO
+  cem.setThresholdValues(2.5, 3.5); //TODO
   cem.work();
   updateImageDisplay();  
 }