Karthik S. Gurumoorthy Anand Rangarajan A Schrödinger Equation for the Fast Computation of Approximate Euclidean Distance Functions. 100-111 2009 SSVM http://dx.doi.org/10.1007/978-3-642-02256-2_9 conf/scalespace/2009 db/conf/scalespace/ssvm2009.html#GurumoorthyR09