Advancing Profilometry Techniques: A Comparative Study of Circular and Linear Fringe Patterns in Digital Fringe Projection

Digital fringe projection profilometry (DFPP) is a well-established technique for three-dimensional surface measurement, traditionally employing vertical or horizontal fringe patterns. This study explores the use of circular fringe patterns in DFPP, aiming to leverage their unique geometric properties to potentially enhance measurement accuracy and robustness. Circular fringes, when projected onto an object, present several potential benefits over conventional linear fringes. Additionally, circular fringes can eliminate the need for a carrier to achieve satisfactory phase development, which may streamline the process and improve efficiency. The projection of circular fringes may inherently smooth the image and reduce noise, potentially reducing the necessity for low-pass filtering and preserving the integrity of high-frequency surface details. The iterative process required to achieve accurate surface reconstruction might be significantly reduced, potentially resulting in faster computation times and more efficient data processing. The inherent symmetry of circular patterns could also simplify phase unwrapping algorithms, as the phase distribution is continuous and naturally wraps around the center point, potentially reducing phase discontinuities and errors. This study presents a comparative analysis of circular versus linear fringe patterns in DFPP, investigating the potential advantages of circular fringes in terms of measurement accuracy, robustness to occlusions, and simplicity in phase unwrapping. Experimental results on various surface profiles suggest that circular fringe projection could be a promising alternative for 3D surface measurement in complex and dynamic environments.