Digital fringe projection (DFP) methods are commonly used to obtain high-accuracy shape measurements. However, many measured objects may have high-contrast texture caused by edges of black- and white-colored sections of the object. In these high-contrast areas, there has consistently been a phase artifact, which in turn creates measurement error, sometimes referred to as “discontinuity-induced measurement artefacts” (DMA). Our study indicated that this error is generally shaped like a Gaussian curve. Based on this finding, we developed a method for removing this error via Gaussian curve fitting on the affected regions. These regions can be found by locating large spikes in the image intensity gradient, which directly correspond to the edge of the Gaussian artifact. We propose to use this error removal method in two ways: to remove errors on a checkerboard calibration target in order to increase calibration accuracy; and to directly remove errors in high-contrast areas to decrease shape measurement error. Experimental results demonstrate that the proposed method can successfully work for decreasing calibration error for a checkerboard calibration target, and shape measurement error can also be significantly decreased as well.
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