Quality assessment of digital speckle patterns for the single-shot speckle projection profilometry based on a visualised simulation platform

Abstract

As a high-speed 3D surface imaging technique, the single-shot speckle projection profilometry (SPP) is widely applied to various fields, where the design of speckle pattern plays a critical role in the fundamental issue of correspondence matching. However, the assessment of speckle patterns in the real imaging system is a time consuming and tedious procedure and their performance might vary with the operators and testing environment. To solve this problem, a visualised simulation platform based on 3ds Max engine is proposed in the paper. Furthermore, the performance of digital speckle patterns (DSPs) on the SPP technique is comprehensively evaluated in terms of 3D reconstruction precision, algorithm efficiency and pattern uniqueness. Firstly, the influence of the noise levels of the projection and imaging processes is considered. Then, the 3D profile reconstruction using five types of speckle pattern is performed in a real experiment. Afterward, a comparative analysis with the optimal DSP is conducted. In addition, the effectiveness of the typical metric of the painted speckle pattern in the field of digital image correlation (DIC) is investigated; results demonstrate its insufficient capability in the SPP field. Moreover, the scaling model of speckle size, influence of speckle deformation and material surface are also discussed to guide the design of DSP. This study can potentially facilitate the selection of high-quality DSPs and the standardisation of the SPP technique. The virtual experiment platform executable file of 3ds Max and the recommended DSP are uploaded as reference.