Single-Shot 3D Shape Measurement Using Speckle-Embedded Colored Fringe Patterns With Neighborhood-Assisted Diffusion Compensation

Abstract

Single-shot structured-light techniques are essential for dynamic 3D measurement. However, speckle-assisted correspondence matching is often affected by correlation mismatches, which severely degrade disparity estimation and reconstruction accuracy. In this paper, a robust single-shot 3D measurement method based on color fringe-speckle pattern is proposed to address correlation-induced mismatches in speckle-assisted correspondence. To suppress unreliable correspondences, a region-based disparity optimization framework is introduced. Specifically, reliable disparity candidates are first identified via density-based clustering within continuous phase regions, effectively eliminating severe mismatches caused by false correlation peaks. Subsequently, a neighborhood-assisted diffusion compensation strategy is applied by exploiting local spatial consistency to recover unreliable or missing disparities, thereby improving disparity completeness. Experimental results on isolated and complex static objects demonstrate that the proposed method significantly improves reconstruction quality. Dynamic experiments involving depth-direction translation and rotational motion further verify that the proposed approach enables stable single-shot 3D reconstruction without noticeable motion-induced artifacts. Quantitative evaluation using a standard sphere shows that the proposed method achieves an RMS accuracy of 0.1 mm. The proposed method enhances the reliability of speckle-assisted single-shot structured-light measurement without requiring additional projected patterns, making it well suited for dynamic 3D sensing applications.