title: Estimation of the orientation term of the general quadrature transform from a single n-dimensional fringe pattern.
abstract: The spatial orientation of the fringe has been demonstrated to be a key point in the reliable phase demodulation from a single n-dimensional fringe pattern regardless of the frequency spectrum of the signal. The recently introduced general n-dimensional quadrature transform (GQT) makes explicit the importance of the fringe orientation in the demodulation process. The GQT is a quadrature operator that transforms cos phi into -sin phi--where phi is the modulating phase--and it is composed of two terms: an orientation factor directly related to the fringe's spatial orientation and an isotropic n-dimensional generalization of the one-dimensional Hilbert transform. We present a method for the determination of the orientation factor in a general n-dimensional case and its application to the demodulation of a single fringe pattern by the GQT. We have tested the algorithm with simulated as well as real photoelastic fringe patterns with good results.
authors.affiliation: Departamento de Optica, Facultad de Ciencias Físicas, Universidad Complutense, Ciudad Universitaria s/n, 28040 Madrid, Spain. aq@fis.ucm.es
authors.forename: J Antonio
authors.initials: JA
authors.lastname: Quiroga
authors.forename: Manuel
authors.initials: M
authors.lastname: Servin
authors.forename: J Luis
authors.initials: JL
authors.lastname: Marroquin
authors.forename: Daniel
authors.initials: D
authors.lastname: Crespo