Jiong Zhong, Remco Duits, Gonzalo Sanguinetti & Bart M. ter Haar Romeny. (2020). Numerical Approaches for Linear Left-Invariant Diffusions on $SE(2)$, Their Comparison to Exact Solutions, and Their Applications in Retinal Imaging. Numerical Mathematics: Theory, Methods and Applications. 9 (1). 1-50. doi:10.4208/nmtma.2015.m1411