Complementary Fusion of Dual-Camera Fringe Projection Profilometry: Toward Accurate 3-D Measurement of Complex-Textured Objects

Abstract

Fringe projection profilometry (FPP) enables high-speed and dense 3-D measurements. However, when objects with complex color textures are measured, unavoidable lens defocus can introduce height jump errors that compromise measurement accuracy. To address this problem, a dual-camera-projector system is constructed, which is decoupled into two single-camera FPP subsystems. By appropriately configuring the relative positions of the two subsystems, height errors with opposite signs are generated, providing complementary error information. The reconstructed height maps are first aligned through phase matching and then iteratively fused to suppress these complementary height jump errors. The experimental results demonstrate that the proposed method reduces height errors on textured objects from more than 1 mm to less than 0.1 mm, representing a reduction of over 90 %. For a standard sphere with complex color textures, the measurement error is reduced from approximately 0.10 to 0.03 mm. Overall, these results confirm that the proposed method can effectively suppress texture-induced height jump errors and improve the accuracy and robustness of FPP for measuring objects with complex color textures.