https://www.nature.com/articles/s41467-021-21326-w.pdf
"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scans of damaged historical documents, but have so far been limited to scrolls, books, and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."
microtomography
microtomography
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Re: microtomography
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That is absolutely astonishing, Bob
... Thanks for the link.
MichaelG.
That is absolutely astonishing, Bob
... Thanks for the link.
MichaelG.
Too many 'projects'