title: Intensity-ratio error compensation for triangular-pattern phase-shifting profilometry.
abstract: We present an intensity-ratio error-compensation method to decrease the measurement error caused by projector gamma nonlinearity and image defocus in triangular-pattern phase-shifting profilometry. The intensity-ratio measurement error is first determined by simulating the measurement with the triangular-pattern phase-shifting method with ideal and real captured triangular-pattern images based on the ideal and real gamma nonlinearity functions. A lookup table that stores the intensity-ratio measurement error corresponding to the measured intensity ratio is constructed and used for intensity-ratio error compensation. Experiments demonstrated that the intensity-ratio error compensation method significantly reduced the measurement error in the triangular-pattern phase-shifting method by 28.5%.
authors.affiliation: Department of Mechanical Engineering, University of Ottawa, 770 King Edward Ave., Ottawa, Ontario, Canada.
authors.forename: Peirong
authors.initials: P
authors.lastname: Jia
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kofman
authors.forename: Chad
authors.initials: C
authors.lastname: English