KPCA plus LDA: a complete kernel Fisher discriminant framework for feature extraction and recognition

TLDR

The study develops a two‑phase kernel Fisher discriminant framework combining kernel PCA and LDA to advance the theory of KFD. The authors introduce the CKFD algorithm, which performs discriminant analysis in double discriminant subspaces and is evaluated on the FERET face and CENPARMI handwritten numeral databases. CKFD leverages both regular and irregular discriminant information, yielding superior performance over existing KFD methods in the experimental tests.

Abstract

This paper examines the theory of kernel Fisher discriminant analysis (KFD) in a Hilbert space and develops a two-phase KFD framework, i.e., kernel principal component analysis (KPCA) plus Fisher linear discriminant analysis (LDA). This framework provides novel insights into the nature of KFD. Based on this framework, the authors propose a complete kernel Fisher discriminant analysis (CKFD) algorithm. CKFD can be used to carry out discriminant analysis in "double discriminant subspaces." The fact that, it can make full use of two kinds of discriminant information, regular and irregular, makes CKFD a more powerful discriminator. The proposed algorithm was tested and evaluated using the FERET face database and the CENPARMI handwritten numeral database. The experimental results show that CKFD outperforms other KFD algorithms.