As I've mentioned before, thanks to the generosity of the American Trust for the British Library, we have been able to embark on a digitisation and online exhibition project for the Sesquicentennial of the American Civil War.  The focus of the work, as well as helping to develop the Library's digitisation processes and platforms, is to reveal to a broader audience the collection items that tell the history of the British role in the War.  More than a cameo, the fortunes of the British Empire (not least many thousands, if not millions, who were born British or Irish) was closely tied to the course and outcomes of the war.  As well as the geo-political implications, there was also the matter of international trade - and, often, the the supply of goods (and other support) to the Confederate South.   This included the printing of stamps for the South, and we hope to include an image of the die used by a British firm for this purpose.

The image shown above, however, is the electrotype of the seal of the Confederate States of America (Seals XLIV.229), dating from 1864 (or, rather, an image of its image being processed on my desktop).  While two-dimensional digital images are fine for most purposes, and especially so for texts, objects such as these lose more than most in the process of being reproduced for an online world.  So, borrowing some of the techniques picked up during the curation of the Growing Knowledge exhibition, we were able to try a method of rendering objects in what appears to be 3D, known as Polynomial Texture Mapping.  A team from Southampton University kindly came to try out their 'PTM' dome, which records a series of images with light cast from various angles.  These are combined into a single file, which can then be manipulated online, giving the effect of a torch being shone on a 3D surface, casting shadows, highlights and different shades.  Inscriptions and erasures may be able to be seen more easily, and the artefact looks much more realistic.

There are problems, however - not least reflections from metal objects, such as the electroplated seal.  So, Southampton was keen to see what can be done with post processing.  I now have the files, and am in the process of rendering the complete PTM file, and working out how to include the viewer in the online gallery for the Civil War project when it finally goes live.

[MJS]