Accelerating fast Fourier transform and filtering operations in Fourier fringe analysis for accurate measurement of three-dimensional surfaces

This paper describes two techniques to accelerate the Fourier fringe analysis technique. The two 2-D Fourier transforms required for the technique are usually a bottleneck for good-quality images in which unwrapping is straight forward. Automation of the filtering operation is an operation that very often requires user interaction when two peaks at similar frequencies are present in the Fourier transform. The techniques presented in this paper attempt to solve these issues. The first technique proposes a reduction in the number of pixels calculated by the Fourier transform. The second, automates the filtering operation to avoid user interaction. (C) 1999 Elsevier Science Ltd. All rights reserved.