“…A projection matrix computed from training data is employed to map the finger-vein images into subspace, and the resulting features are further used for recognition. The typical methods include principal component analysis (PCA) (Wu and Liu, 2011a ), two dimensional principal component analysis (2DPCA) (Qiu et al, 2016 ), two-directional and two-dimensional principal component analysis ((2D)2PCA) (Yang et al, 2012 ; Li et al, 2017 ; Zhang et al, 2021 ; Ban et al, 2022 ; She et al, 2022 ), linear discriminant analysis (LDA) (Wu and Liu, 2011b ), high-dimensional state space (Zhang et al, 2022 ), self-feature-based method (Xie et al, 2022 ), and latent factor model (Wu et al, 2022 ).…”