I'm one of the authors of this paper, and
ran across your posts. I thought folks might be interested in our website where you can see more coin examples that use the technique and can be interactively viewed with different lighting.
http://www.c-h-i.org/examples/ptm/ptm.html is the
index page, and there is a coin
gallery available. You need a Java enabled browser to look at them. The demos are low resolution due to web constraints, but we shoot at a much higher resolution, that allows you to zoom in and out.
You can also learn more about this technique, in a less academic format, from this article on our website:
http://www.c-h-i.org/technology/ptm/ptm.htmlThis technique is quite different from photogrammetry (something we also use) in that it generates 3D information based on the reflectance properties of the surface, and stores it in a 2D format. This surface information allows you to see
fine detail of the surface characteristics, more than you would get from a 3D model, and with enhancements, more than you can see on the object itself. Also the technique works on highly reflective material, which is very difficult to capture with traditional 3D scanning and imaging techniques. The article I mention has a
good explanation of what's going on for those who are interested. The technique has been used to decipher heavily worn and/or corroded inscriptions, most famously on the Greek Antikythera mechanism.
http://www.hpl.hp.com/research/ptm/antikythera_mechanism/index.htmlAnd finally, there is a new technique for capturing this
type of image that we developed last year in conjunction with HP labs that doesn't require a light dome. So, it's easy to try out without investing a lot, and it's more flexible for different size objects. We've been using it for documenting rock art.
We are a 501(c)(3) non-profit corporation, and the
software we develop will be made available as open source. We have some active projects and expect to make more stuff available during 2008.
Thanks for your interest!
Carla