Evaluating and propagating uncertainty in digital fringe projection systems

Fringe projection is a measurement technique able to produce high-density data measurements of Lambertian surfaces using a camera and projector. Evaluating the uncertainty of a fringe projection system is challenging because of the highdensity and the interdependence of data involved in both characterising the instrument parameters and conducting the measurement. Fringe projection systems undergo a characterisation process to define the parameters that triangulate the surface points from camera images. The accuracy of the parameters defined during the characterisation process will partly define the accuracy of the final measurement. The characterisation process is often called “calibration” – yet does not provide a value of uncertainty of the parameter values found during characterisation. This paper outlines a method to allow the evaluation of uncertainty in a fringe projection system caused by imperfect characterisation procedures before applying this method to a flat plane artefact and a sphere plate artefact