Graph-based semi-supervised learning has gained considerable
interests in the past several years thanks to its effectiveness
in combining labeled and unlabeled data through
label propagation for better object modeling and classification.
A critical issue in constructing a graph is the weight
assignment where the weight of an edge specifies the similarity
between two data points. In this paper, we present a novel
technique to measure the similarities among data points by
decomposing each data point as an L1 sparse linear combination
of the rest of the data points. The main idea is that
the coefficients in such a sparse decomposition reflect the
point’s neighborhood structure thus providing better similarity
measures among the decomposed data point and the
rest of the data points. The proposed approach is evaluated
on four commonly-used data sets and the experimental
results show that the proposed Sparsity Induced Similarity
(SIS) measure significantly improves label pr...