Abstract:Aiming at the unsupervised and timeconsuming l1 norm optimization problems of the existing sparsity preserving projection, a novel fast feature extraction algorithm named sparsity preserving laplacian discriminant analysis (SPLDA) is proposed. SPLDA first creates a concatenated dictionary via classwise principal component analysis(PCA) decompositions and learns the sparse representation structure of each sample under the dictionary using the least square method. Then SPLDA considers both the sparse representation structure and the discriminative efficiency by regularizing the Laplacian discriminant function from the learned sparse representation structure. Finally, the proposed method is transformed into a generalized eigenvalue problem. Extensive experiments on several popular face databases (Yale, Olivetti Research Laboratory(ORL) and Extended Yale B) are provided to validate the feasibility and effectiveness of the proposed algorithm.