With ever-increasing demand for three-dimensional (3D) imaging and shape measurements in a variety of fields, measurement accuracy has become of vital importance to numerous scientific and engineering applications. This paper presents an experimental investigation into the accuracy comparison of two prevalent 3D imaging and shape measurement methods: fringe projection profilometry (FPP) and 3D digital image correlation (3D-DIC) techniques. A detailed description of their principles reveals their inherent similarities and fundamental differences. A measurement system composed of both techniques is employed in the study, and a test target with speckle checkerboard patterns on its surface is adopted to allow simultaneous FPP and 3D-DIC measurements. The evaluation puts emphasis on how the geometric angles between key hardware components affect the 3D measurement accuracy. Experiments show that the depth and height measurements of both techniques can reach sub-micron accuracy, and the relative accuracy of the 3D shape or position measurements can reach 1/600 000.

随着在各个领域对三维（3D）成像和形状测量的需求不断增长，测量精度对于众多科学和工程应用已变得至关重要。本文对两种流行的3D成像和形状测量方法（条纹投影轮廓仪（FPP）和3D数字图像相关性（3D-DIC）技术）的精度比较进行了实验研究。对它们的原理的详细描述揭示了它们固有的相似性和根本差异。在这项研究中，采用了两种技术组成的测量系统，并采用了表面带有斑点棋盘图案的测试目标，以便同时进行FPP和3D-DIC测量。评估重点放在关键硬件组件之间的几何角度如何影响3D测量精度上。实验表明，两种技术的深度和高度测量都可以达到亚微米精度，而3D形状或位置测量的相对精度可以达到1/600 000。