This work has been supported by the NSF Medium ITR IIS-0205586.
Image processing -- Digital techniques, Three-dimensional imaging, Photometry
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 m (or more) and depth resolutions of approximately 2 m. 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 m as this is approximately the minimum resolution deemed necessary to accurately represent cuneiform.
D. V. Hahn, K. C. Baldwin, D. D. Duncan, “Non-laser based scanner for 3D digitization of historical artifacts,” Applied Optics, V. 46, pp. 2838-2850 (2007)