diff --git a/geometry.cpp b/geometry.cpp
index 93df776..456c1f3 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -110,3 +110,23 @@ is_above_line(cv::Vec<double,3> line, Point p)
 {
     return line(0)*p.x + line(1)*p.y + line(2) > 0;
 }
+
+cv::Point
+further_point_from_line(cv::Vec<double,3> line, std::vector<Point> points)
+{
+    //distance = abs(a*p.x+b*p.y+c) / sqrt(a^2+b^2)
+    double denom = sqrt(line(0)*line(0)+line(1)*line(1));
+    Point further = points[0];
+    double maxdist = -1;
+    std::cout << "--- further" << std::endl;
+    for(Point p: points)
+    {
+        double numerator = abs(line(0)*p.x + line(1)*p.y + line(2));
+        double distance = numerator/denom;
+        if(distance > maxdist) {
+            maxdist = distance;
+            further = p;
+        }
+    }
+    return further;
+}
diff --git a/geometry.h b/geometry.h
index 9eb6143..3fc079f 100644
--- a/geometry.h
+++ b/geometry.h
@@ -11,6 +11,7 @@ cv::Point unmap_point(double, cv::Point, cv::Point);
 cv::Vec<double,3> get_line(cv::Point, cv::Point);
 bool is_in_line(cv::Vec<double,3> line, cv::Point p);
 bool is_above_line(cv::Vec<double,3> line, cv::Point p);
+cv::Point further_point_from_line(cv::Vec<double,3>, std::vector<cv::Point>);
 
 class CoordinateSystem
 {
diff --git a/lines.cpp b/lines.cpp
index 7d00930..e37fea1 100644
--- a/lines.cpp
+++ b/lines.cpp
@@ -44,7 +44,6 @@ int main(int argc, char *argv[])
 	cv::findContours(img,contours,hierarchy,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE);
 
 	unsigned short dotwidth = img.cols >> 6;  // divide by 64, so efficient
-	//img = cv::imread(fname,CV_LOAD_IMAGE_COLOR); // uncomment to this to display image with colors
 	cv::drawContours(img,contours,-1,BROWN,dotwidth>>4);
 
 	if( 0==contours.size() ) {
@@ -77,10 +76,6 @@ int main(int argc, char *argv[])
 	img = cv::imread(fname,CV_LOAD_IMAGE_COLOR); // uncomment to this to display image with colors
 	std::cout << "Maxdist1:" << maxdistances[0] << " " << corn_1 << corn_2 << std::endl;
 	std::cout << "Maxdist2:" << maxdistances[1] << " " << corn_3 << corn_4 << std::endl;
-	cv::circle(img,corn_1,dotwidth>>1,MAGENTA,2);
-	cv::circle(img,corn_2,dotwidth>>2,MAGENTA,2);
-	cv::circle(img,corn_3,dotwidth>>2,BROWN,2);
-	cv::circle(img,corn_4,dotwidth>>2,BROWN,2);
 	cv::namedWindow("win", CV_GUI_NORMAL);
 	// cv::imshow("4 corners",img);
 	// cv::waitKey(0);
@@ -94,26 +89,8 @@ int main(int argc, char *argv[])
 	verticals.push_back(find_longest_line(hull, (maxdistances[1]+1)%hull.size(), maxdistances[0]));
 	free(maxdistances);
 
-#ifdef _DEBUG
-	//img = cv::imread(fname,CV_LOAD_IMAGE_COLOR); // uncomment to this to display image with colors
-	auto color = MAGENTA;
-	for( auto line: verticals )
-	{
-		color = (color==BLUE) ? MAGENTA : BLUE; //flip color for the two lines
-		cv::Point p1 = line[0];
-		cv::Point p2 = line[line.size()-1];
-		cv::line(img, p1, p2, color, dotwidth>>4);
-		std::cout << "vertical: " << line[0] << line[line.size()-1] << std::endl;
-		for(cv::Point p: line)
-		{
-			cv::circle(img,p,dotwidth>>3,color,-1);
-		}
-	}
-#endif
-
 	// theta is the angle of the line connecting point 1 and 2; it will be the
 	// rotation of our new coordinate system
-	double theta = atan(((double)corn_2.y-corn_1.y) / ((double)corn_2.x-corn_1.x));
 	auto cs = CoordinateSystem(corn_1, corn_2);
 	assert(cs.map(corn_1).x == 0);
 	assert(cs.map(corn_1).y == 0);
@@ -122,24 +99,40 @@ int main(int argc, char *argv[])
 	cv::Vec<double,3> diag1, diag2;
 	diag1 = get_line(cs.map(corn_1), cs.map(corn_3));
 	diag2 = get_line(cs.map(corn_4), cs.map(corn_2));
-	cv::line(img, corn_1, corn_3, BLUE, dotwidth>>4);
-	cv::line(img, corn_2, corn_4, MAGENTA, dotwidth>>4);
 	std::cout << "mapped diag1: " << diag1 << std::endl;
 	std::cout << "mapped diag2: " << diag2 << std::endl;
 
+	std::vector<cv::Point> points1, points2;
 	for(cv::Point p: contour)
-	{
+	{ // the point is interesting where it is above both lines or below both lines
 		cv::Point mapped = cs.map(p);
-		if(is_above_line(diag1, mapped) == is_above_line(diag2, mapped)) {
-			cv::circle(img, p, dotwidth>>3, YELLOW,-1);
+		if(is_above_line(diag1, mapped)) {
+		   if(is_above_line(diag2, mapped)) {
+			points1.push_back(p);
+		   }
+		} else {
+		   if(!is_above_line(diag2, mapped)) {
+			points2.push_back(p);
+		   }
 		}
 	}
 
 #ifdef _DEBUG
+	cv::Point middle1 = further_point_from_line(get_line(corn_1, corn_2), points2);
+	cv::Point middle2 = further_point_from_line(get_line(corn_3, corn_4), points1);
+	cv::line(img, corn_1, middle1, MAGENTA, dotwidth>>3);
+	cv::line(img, corn_2, middle1, MAGENTA, dotwidth>>3);
+	cv::line(img, middle1, middle2, BLACK, dotwidth>>4);
+	cv::line(img, corn_3, middle2, MAGENTA, dotwidth>>3);
+	cv::line(img, corn_4, middle2, MAGENTA, dotwidth>>3);
+	cv::line(img, corn_2, corn_3, BLUE, dotwidth>>4);
+	cv::line(img, corn_1, corn_4, BLUE, dotwidth>>4);
+	std::cout << middle1 << middle2 << std::endl;
+
 	cv::imshow("win",img);
 	while(1)
 	{
-		if( cv::waitKey(0) == 113 )
+		if( (char)cv::waitKey(0) == 113 )
 			break;
 	}
 	img.release();