diff --git a/canny_edge_machine.cpp b/canny_edge_machine.cpp
index 464cf21..12688ae 100644
--- a/canny_edge_machine.cpp
+++ b/canny_edge_machine.cpp
@@ -26,6 +26,7 @@ class CannyEdgeMachine {
     int* gradient_y;
     
     // Params
+    int filter_size;
     double t_low;
     double t_high;
     
@@ -53,6 +54,10 @@ class CannyEdgeMachine {
       free(this->gradient_y);
     };
     
+    void setGaussFilterSize(int filter_size) {
+      this->filter_size = filter_size;
+    };
+    
     void setThresholdValues(double t_low, double t_high) {
       this->t_low = t_low;
       this->t_high = t_high;
@@ -68,9 +73,9 @@ class CannyEdgeMachine {
       }
     };
     
-    void doGaussBlur(int filter_width=3) {
+    void doGaussBlur(int filter_width) {
       // build the gauss filter
-      int* filter = (int*) malloc(sizeof(int) * filter_width* filter_width);
+      int* filter = (int*) malloc(sizeof(int) * filter_width * filter_width);
       int sum_weights = 0;
       int filter_middle = (filter_width)/2;
       for(int x=0; x<filter_width; x++) {
@@ -266,7 +271,7 @@ class CannyEdgeMachine {
     
     void work() {
       this->reset();
-      this->doGaussBlur();
+      this->doGaussBlur(this->filter_size);
       this->doGradiants();
       this->doGradiantMagnitude();
       this->filterLocalMaxima();
diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index b903564..316b6f6 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -649,8 +649,8 @@ void ImageViewer::applyBasicFilterWithOverflowHandling() {
  * @brief ImageViewer::runCannyEdge 
  */
 void ImageViewer::runCannyEdge(void) {
-  //TODO
   CannyEdgeMachine cem = CannyEdgeMachine(original, working_copy);
+  cem.setGaussFilterSize(3);
   cem.setThresholdValues(2.5, 3.5); //TODO
   cem.work();
   updateImageDisplay();