Although this requires much more work and more tests with different objects, it could be a somewhat interesting method to better distinguish inscriptions present on coins or small object.

The picture above is of a Medieval lead stopper or weight found at the site of Caerau, Cardiff, which has been made into a 3D model using 123D Catch and then run through a filter in Meshlab (all freeware).

Meshlab itself is an interesting but somewhat limited program, but the Colorize Curvature (APSS) filter seems promising, as it changes the texture colour based on the inclination of the surface. The papers regarding the filter are extremely technical, which at the moment make it difficult for me to understand the process in detail, but with an extremely high MSL – Spherical Parameter (even 10000000000) and an approximate mean Curvature Type the results above come out.

The stopper seems to bear three letters on the top (EXQ?) and maybe something at the bottom too.

At present the only other object I’ve tried is a piece of pot with decoration, but the natural curve of the object itself made it hard to achieve anything. However the way the filter works seems to suggest that there is indeed correlation between the inscription above and the filter rather than a random effect that just so happened to produce the image. Research continues…