MIT Developing Imaging Algorithms To Read Letter Inside Unopened Envelope

Unfolding a locked letter Photo: Signed, Sealed and Undelivered Team, courtesy of the Museum voor Communicatie, The Hague.

Researchers from the MIT “Signed, Sealed, and Undelivered” (SSU) Project are developing imaging algorithms that will, for all practical purposes, allow them to read a letter still inside its unopened envelope.

The specific letters they are attempting to read are 2,600 17th-century letters belonging to the Brienne Collection. An interesting characteristic of each of these letters is that it is folded and sealed in such a way as to function as its own envelope. Simply trying to open these letters may result in tears and damages.

All of the letters in the Brienne collection, the documents examined in the SSU project, are examples of “letterlocking,” a centuries-old practice of folding and securing a letter to function as its own envelope. The physical details of the elaborately cut, folded, and sealed paper often have as much to tell us as the text.

Using cutting-edge x-ray imaging technology developed in the field of dentistry, the researchers want to be able to digitize the letters without opening and flattening them out.

Researchers in x-ray microtomography imaging at Queen Mary University of London have scanned 10 model letters and sent the data back to MIT. The SSU team will now use those x-ray images to develop their algorithms and hope to be able to soon virtually unfold and read the precious 17th-century artifacts in the Brienne Collection without tearing the paper or breaking the seals.