“…Some recent advances in PCA-based algorithms include multi-linear subspace analysis [90], symmetrical PCA [91], two-dimensional PCA [92,93], eigenbands [94], adaptively weighted subpattern PCA [95], weighted modular PCA [96], Kernel PCA [97,98] and diagonal PCA [99]. Examples of recent LDA-based algorithms include Direct LDA [100,101], Direct-weighted LDA [102], Nullspace LDA [103,104], Dual-space LDA [105], Pair-wise LDA [106], Regularized Discriminant Analysis [107], Generalized Singular Value Decomposition [108,109], Direct Fractional-Step LDA [110], Boosting LDA [111], Discriminant Local Feature Analysis [112], Kernel PCA/LDA [113,114], Kernel Scatter-Difference-based Discriminant Analysis [115], 2D-LDA [116,117], Fourier-LDA [118], Gabor-LDA [119], Block LDA [120], Enhanced FLD [121], Component-based Cascade LDA [122], and incremental LDA [123], to name but a few. All these methods purportedly obtain better recognition results than the baseline techniques.…”