{Extracting features by transforming the feature space, e.g. multidimensional scaling; Mappings, e.g. subspace methods based on an approximation criterion, e.g. principal component analysis nonlinearly, e.g. embedding a manifold in a Euclidean space }
{Extracting features by transforming the feature space, e.g. multidimensional scaling; Mappings, e.g. subspace methods based on an approximation criterion, e.g. principal component analysis nonlinearly, e.g. embedding a manifold in a Euclidean space }