Patent ID: 6639685
Filing Date: 2003-10-28
Classification: G01B,G06T

Abstract:
An image processing method for extracting information from a fringe pattern produced by an optical measurement of an object, comprising the steps of:(a) recording a single image of the fringe pattern; (b) determining one or more estimated fringe spacings using fringe lines contained within the image; (c) generating a plurality of phase-shifted image data sets using the image and the estimated fringe spacing(s); (d) generating wrapped phase information using the phase-shifted image data sets; (e) unwrapping the phase information and generating a set of data points representative of the unwrapped phase information; (f) performing at least one iteration of the following steps (f1) and (f2): (f1) determining an updated estimated fringe spacing for each of a number of the data points using a curve fitting function; and (f2) repeating steps (c), (d) and (e) using the updated estimated fringe spacings; and (g) generating output data representing information contained in the fringe pattern using the unwrapped phase information determined during the final iteration of step (e).