The random walker algorithm was introduced in the paper: Leo Grady and Gareth Funka-Lea, "Multi-Label Image Segmentation for Medical Applications Based on Graph-Theoretic Electrical Potentials", in Proceedings of the 8th ECCV04, Workshop on Compute

Contains the matlab code for various focus measures used in image processing applications such as multi focus image fusion/autofocus and so on. It has the implementations according to the paper (http://www.sciencedirect.com/science/article/pii/S003