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Non-Laser-Based Scanner For Three-Dimensional digitization of historical artifacts
Applied Optics Vol. 46, No. 15, 20 May 2007
Daniel V. Hahn, Kevin C. Baldwin, and Donald D. Duncan

ABSTRACT: 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.

Digital Hammurabi: Design and Development of a 3D Scanner for Cuneiform Tablets
Proceedings of SPIE. 6056. pp. 130-141. 2006
Daniel V. Hahn, Donald D. Duncan, Kevin C. Baldwin, Jonathan D. Cohen, Budirijanto Purnomo

ABSTRACT:... we describe a 3D scanner capable of acquiring the shape, color, and reflectance of a tablet as a complete 3D object. ...The scanner utilizes a camera and telecentric lens to acquire images of the tablet under varying controlled illumination conditions. Image data are processed using photometric stereo and structured light techniques to determine the tablet shape; color information is reconstructed from primary color monochrome image data. The scanned surface is sampled at 26.8 micron lateral spacing and the height information is calculated on a much smaller scale. Scans of adjacent tablet sides are registered together to form a 3D surface model.

iClay: Digitizing Cuneiform
VAST 2004 Conference, Brussels, December 2004
Jonathan Cohen, Donald Duncan, Dean Snyder, Jerrold Cooper, Subodh Kumar, Daniel Hahn, Yuan Chen, Budirijanto Purnomo, and John Graettinger

ABSTRACT: Advances in digital technology for the graphic and textual representation of manuscripts have not, until recently, been applied to the world's oldest manuscripts, cuneiform tablets. This is due in large part both to the three-dimensional nature of cuneiform tablets and to the complexity of the cuneiform script system. The Digital Hammurabi Project and the Initiative for Cuneiform Encoding announce success in encoding Sumero-Akkadian cuneiform in Unicode while also demonstrating advances in 3D scanning and visualization of cuneiform tablets, showcased by iClay, a cross-platform, Internet-deployable, Java applet that allows for the viewing and manipulation of 2D+ images of cuneiform tablets.

Seamless Texture Atlases
Proceedings of 2nd Eurographics/ACM Symposium on Geometry Processing. pp. 67-76. 2004
Budirijanto Purnomo, Jonathan D. Cohen, Subodh Kumar

ABSTRACT: Texture atlas parameterization provides an effective way to map a variety of color and data attributes from 2D texture domains onto polygonal surface meshes. However, the individual charts of such atlases are typically plagued by noticeable seams. We describe a new type of atlas which is seamless by construction. Our seamless atlas comprises all quadrilateral charts, and permits seamless texturing, as well as per-fragment down-sampling on rendering hardware and polygon simpli cation. We demonstrate the use of this atlas for capturing appearance attributes and producing seamless renderings.

More to come...