Non-laser-based scanner for three-dimensional digitization of historical artifacts

摘要

A 3D scanner, based on incoherent illumination techniques, and associated data-processing algorithms are presented that can be used to scan objects at lateral resolutions ranging from 5 to 100 μm (or more) and depth resolutions of approximately 2 μm. The scanner was designed with the specific intent to scan cuneiform tablets but can be utilized for other applications. Photometric stereo techniques are used to obtain both a surface normal map and a parameterized model of the object's bidirectional reflectance distribution function. The normal map is combined with height information, gathered by structured light techniques, to form a consistent 3D surface. Data from Lambertian and specularly diffuse spherical objects are presented and used to quantify the accuracy of the techniques. Scans of a cuneiform tablet are also presented. All presented data are at a lateral resolution of 26.8 μm as this is approximately the minimum resolution deemed necessary to accurately represent cuneiform.