Principal component analysis (PCA)-like methods make use of an estimation o
f the covariances between sample variables. This estimation does not take i
nto account their topological relationships. This paper proposes how to use
these relationships in order to estimate the covariances in a more robust
way. The new method topological principal component analysis (TPCA) is test
ed using both face encoding and recognition experiments showing how the gen
eralization capabilities of PCA are improved. (C) 2001 Elsevier Science B.V
. All rights reserved.