title: Formulation and implementation of a phase-resolved fluorescence technique for latent-fingerprint imaging: theoretical and experimental analysis.
abstract: A theoretical and experimental study of the imaging of latent fingerprints by a phase-resolved fluorescence technique along with associated signal-processing analysis is described. The system configuration is optimized by incorporation of a novel approach of homodyne-assisted even-step phase shifting in a signal-processing concept. The excitation laser source and gain of the detection device, which are modulated at megahertz frequency followed by sensitive signal-processing concepts, are employed to separate the fingerprint fluorescence from background fluorescence. Experiments are carried out with fingerprints deposited upon different types of substrate surfaces. Later, a quantitative image-quality assessment is carried out, which confirms the improvement in the quality of the phase-resolved fingerprint image. Imaging of older fingerprints with better contrast is also carried out with the proposed novel technique.
authors.affiliation: School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798.
authors.forename: U S
authors.initials: US
authors.lastname: Dinish
authors.forename: Z X
authors.initials: ZX
authors.lastname: Chao
authors.forename: L K
authors.initials: LK
authors.lastname: Seah
authors.forename: A
authors.initials: A
authors.lastname: Singh
authors.forename: V M
authors.initials: VM
authors.lastname: Murukeshan