Determination of height pro le from a two-dimensional fringe signal using a two-dimensional continuous wavelet transform

Abstract

The main objective of this study was 3-dimensional (3D) pro le measurements with standard fringe projection, consisting of a CCD and a projector. For obtaining height information of objects pixel by pixel, phases have to be calculated from the images taken by the fringe projection technique. In this study, the 2-dimensional continuous wavelet transform (2D CWT) phase method was used for phase extraction. 1D and 2D CWT analyses of noisy images were compared in simulations performed for a 2-dimensional fringe signal by introducing the carrier frequencies in two spatial directions, x and y . Pro le measurement of an object was made experimentally by cross optical axis geometry. Images, using fringes with two carrier frequencies, taken from this setup were analyzed with 2D CWT and 3D pro les of objects were obtained. Numerical simulations and actual experiments were carried out to show the validity of this technique for nding phase distributions from noisy images