Fast 3-D Measurement Based on Spatial-temporal Speckle Projection

Speckle projection profilometry (SPP), as a promising structured light projection technique, can achieve global unambiguous 3D measurement by projecting a single random speckle pattern. However, due to the measured surfaces with complex reflection characteristics and the perspective differences between stereo cameras, only projecting a single speckle pattern is difficult to encode a globally unique feature for every pixel in the whole measurement space, resulting in its limited measurement accuracy. To meet the high-precision measurement requirement of industrial scenes, this paper proposed a 3D measurement method based on spatial-temporal speckle projection (STSP), which obtain the depth information of the measured scene efficiently by integrating 10 speckle projection modules. Experimental results demonstrate that, within the measurement range of 0.8m-2.0m, the proposed method can achieve fast and high-precision 3D measurement with the accuracy of 0.43mm at 0.85m.