Paper by Erik D. Demaine
- Jana Dambrogio, Amanda Ghassaei, Daniel Starza Smith, Holly Jackson, Martin L. Demaine, Graham Davis, David Mills, Rebekah Ahrendt, Nadine Akkerman, David van der Linden, and Erik D. Demaine, “Unlocking history through automated virtual unfolding of sealed documents imaged by X-ray microtomography”, Nature Communications, volume 12, March 2021, Article 1184.
Computational flattening algorithms have been successfully applied to X-ray
microtomography scans of damaged historical documents, but have so far been
limited to scrolls, books, and documents with one or two folds. The challenge
tackled here is to reconstruct the intricate folds, tucks, and slits of
unopened letters secured shut with “letterlocking,” a
practice—systematized in this paper—which underpinned global
communications security for centuries before modern envelopes. We present a
fully automatic computational approach for reconstructing and virtually
unfolding volumetric scans of a locked letter with complex internal folding,
producing legible images of the letter's contents and crease pattern while
preserving letterlocking evidence. We demonstrate our method on four
letterpackets from Renaissance Europe, reading the contents of one unopened
letter for the first time. Using the results of virtual unfolding, we situate
our findings within a novel letterlocking categorization chart based on our
study of 250,000 historical letters.
- This paper is available from Nature.
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Last updated December 15, 2022 by