3D shape measurement of shiny surfaces based on optimized combination of fringe patterns of different intensity

Image saturation is a challenging problem for three-dimensional shape measurement of objects with shiny surfaces using fringe projection profilometry technology. This paper presents a new method based on projection of multiple fringe patterns, providing an effective solution to the problem. First, a set of phase shifted sinusoidal fringe patterns with different intensity levels are projected to the object of interest, and the reflections are captured by the camera. With the captured images a set of masks are created, which are able to pick up the unsaturated data from the captured images. The unsaturated data are then combined based on maximal Signal-to-noise Ratio (SNR) scenario, and the combined images are used to retrieve the phase information. Comparing to existing methods, the proposed technique is advantageous by improved measurement accuracy due to the improved SNR. The performance of the proposed method is verified by the experiments.

Automated summary

This paper presents a new method based on projection of multiple fringe patterns to solve the challenging problem of image saturation in three-dimensional shape measurement of objects with shiny surfaces. By projecting a set of phase shifted sinusoidal fringe patterns with different intensity levels, creating masks to pick up unsaturated data, combining unsaturated data based on maximal Signal-to-noise Ratio (SNR), and using the combined images to retrieve phase information, the proposed technique shows improved measurement accuracy due to enhanced SNR. The performance of the method is verified through experiments.