3D printed control for commercial off-the-shelf (COTS) close-range photogrammetric reconstruction

The use of photogrammetry in archaeology and anthropology has become increasingly popular over the past decade. If the intended purpose of a three-dimensional (3D) model generated by commercial “off-the-shelf” (COTS) photographic equipment is geometric analysis or preservation by record, appropriate 3D control is recommended to improve orientation estimates and, in turn, the accuracy of the output 3D model. Further, independent measures of the quality of the photogrammetric model (in addition to the 3D model output itself) are recommended for robust validation. This paper evaluates the use of bespoke 3D printed designs (cradles) to add both control points to close-range 3D model and check points for validation. There were no statistically significant differences between the control and check points errors and intra-observer error was low and comparable to conventional manual measurement methods, thus providing an accessible method of adding 3D control to close-range photogrammetry.