Random Walks for Image Segmentation

by Leo Grady

This paper proposed a random walk based algorithm for image segmentation. The idea is quite straightforward: some part of the images are labeled by the user and other areas are segmented using the random walk probability that stops at these landmarks.

The interesting part of the paper is that it proposed a (several) linear system to solve the probability, instead of solving an eigenvalue problem.

L_U X = -B

where L_U is the graph Laplacian of the unlabelled samples and the B is the cross block in the Laplacian of the whole graph.

The idea was used in t-SNE to build p-table for landmarks.