Seeing the Codex Vercellensis in a New Light: Multispectral Imaging and the Old Latin Bible

I’m pleased to be able to post here a report of some important new research from Gregory Heyworth and Roger Easton which will doubtless be of broader interest:

Dating to the first half of the 4th century, the Codex Vercellensis or Codex A is the earliest manuscript of the Gospels in Latin. As such, it is perhaps the closest witness to the text of the Christian Bible in the West in the age of Constantine and the Council of Nicaea. Housed in the Capitulary Library of Vercelli since the time of St. Eusebius of Vercelli under whose auspices it was written, the manuscript now contains 317 folios, many of which are badly damaged by mold and decay to the point of illegibility. In fact, the last edition of Codex A to be made from an original reading of the manuscript was in the mid 18th century when it was considerably more legible than it is today.

          To stabilize the crumbling manuscript, Franz Ehrle, head conservator at the Vatican in the early 20^th century, disbound it and encased each bifolium in thin sheets of gelatin. While effective in preventing further decay, the gelatin also inhibits ultraviolet light which scholars have traditionally used to enhance reading through fluorescence. In an effort return Codex A to the attention of scholars, the curator of the Capitulary Library and Museum of the Dome, Timoty Leonardi, contacted the Lazarus Project for assistance in recovering text from the manuscript.

          In March 2013, a team from the Lazarus Project (http://www.lazarusprojectimaging.com/) traveled to Vercelli to collect spectral images of sample leaves from the codex. In July 2014 they returned to image the entire manuscript, this time with help from the Early Manuscripts Electronic Library (http://emel-library.org/).

          Spectral imaging involves two distinct phases. First, imagers photograph the manuscript with a 50-megapixel camera fitted with a specially calibrated quartz lens and a dual filter wheel. 

 Specially designed LED light units illuminate each folio both from above (reflectively) and below (transmissively) in twelve different wavelengths of light between the ultraviolet (365nm) and the infrared (940nm). Fluorescence from the manuscript provoked by ultraviolet and blue light is separated and captured with the help of a dual filter wheel that sits in front of the lens. All told, as many as thirty-three individual images of each page are captured by the computer-driven system, totaling in this case over 20,000 photos in a ten day period and over 4 terabytes of data.

          In the image processing phase, combinations of these bands are computed digitally using a hypersectral software called ENVI that is traditionally used for processing geospatial images from satellites. The goal is to enhance the contrast of the text to the background. The image “cubes” are then further refined using statistical processing known as Principle Component Analysis (PCA) and Independent Component Analysis (ICA). In this example, pseudocolor images with different combinations of spectral bands were animated to show how the text looks before and after image processing.

          The key to the effectiveness of a spectral imaging project lies in the interdisciplinarity of the team. Led by Dr. Gregory Heyworth, a medievalist and codicologist trained in textual editing, the Lazarus Project team is comprised of imaging scientists Drs. Keith Knox and Roger Easton, both of whom are known for their pioneering work on the Archimedes Palimpsest among many other major recovery intitiatives. They were joined by Michael Phelps, Executive Director of EMEL, a biblical scholar by training, who directs the Sinai palimpsest project at St. Catherine’s monastery, and by Ken Boydston of MegaVision Corporation, who constructed the camera system and designed the lens, and who is known, among other things, for his work imaging the Dead Sea Scrolls multispectrally. The team was rounded out by a number of undergraduate students from the University of Mississippi and the Rochester Institute of Technology who are learning the interdisciplinary skills of textual science necessary to broaden the awareness of this esoteric field for the next generation.

          The result of the first imaging is shown in the animation video. Much of the text that is unreadable to the unaided eye reveals itself in the spectral images. Processing of images of the entire manuscript is now ongoing. Additional results are expected by the end of summer 2015, to be followed by a new edition by Heyworth under the auspices of the Vetus Latina Institute.