I have an improvement to this: Run the edge detection twice. That way you get better gradients along sharp edges. Single run: http://i.imgur.com/kusJDRo.png h

I have an improvement to this: Run the edge detection twice. That way you get better gradients along sharp edges. Single run: http://i.imgur.com/kusJDRo.png http://i.imgur.com/kusJDRo.png Double run: http://i.imgur.com/rHYSzpq.png http://i.imgur.com/rHYSzpq.png To me, at least, the double looks better. Especially in the stems. Just add the following to FrequencyTable.cs, after line 18 (var edges = ...) detector = new SobelEdgeDetector(); edges = detector.Apply(edges);