Relative Agreement and Feasibility of Low-Cost Passive Stereophotogrammetry for Nasal Three-Dimensional Surface Imaging: A Comparison of COLMAP and Agisoft Metashape with a Handheld Structured-Light Scanner

Portable handheld three-dimensional (3D) scanners have improved facial surface measurement workflows in plastic and reconstructive surgery and have potential applications in preoperative planning, postoperative assessment, and customized implant design. However, the relative agreement of low-cost passive stereophotogrammetry for nasal surface reconstruction remains insufficiently characterized when compared with handheld structured-light scanning. This study evaluated the feasibility and relative surface-deviation performance of two passive stereophotogrammetry-based systems for nasal 3D surface reconstruction in healthy participants. Twenty-five healthy participants were enrolled, and nasal 3D models were reconstructed using Artec Eva, COLMAP, and Agisoft Metashape. COLMAP- and Agisoft Metashape-derived models were aligned to the corresponding Artec Eva models in MeshLab. Geometric deviations were quantified using root mean square (RMS) surface deviation, mean surface distance (MSD), and Hausdorff distance (HD), and regional discrepancies were visualized using surface-distance heat maps. Both passive pipelines produced deviations generally within previously reported ranges for facial or nasal 3D imaging, with median RMS and MSD values below 0.5 mm. Hausdorff distance showed larger local deviations, particularly in the alar and perinasal regions, and was significantly lower for Agisoft Metashape than for COLMAP. These findings suggest that low-cost passive stereophotogrammetry may support standardized nasal surface measurement under controlled acquisition conditions.