diff --git a/canny_edge_machine.cpp b/canny_edge_machine.cpp
index c463461..68da4b1 100644
--- a/canny_edge_machine.cpp
+++ b/canny_edge_machine.cpp
@@ -261,9 +261,9 @@ class CannyEdgeMachine {
 	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);
+	  } else {
+	    this->working_copy->getImage()->setPixel(x, y, white);
 	  }
 	}
       }
@@ -271,11 +271,13 @@ class CannyEdgeMachine {
     
     void work() {
       this->reset();
-      this->doGaussBlur(this->filter_size);
+      this->doGaussBlur(this->filter_size); // uses filter_size
       this->doGradiants();
       this->doGradiantMagnitude();
-      this->filterLocalMaxima();
-      this->workLocalMaxima();
+      // TODO: Checkpoint for 'before t_low changed'
+      this->filterLocalMaxima(); // uses t_low only
+      // TODO: Checkpoint for 'before t_high changed'
+      this->workLocalMaxima(); // uses t_low & t_high
       this->showEdges();
     };