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Livingstone's Letter from Bambarre

A Multispectral Critical Edition

All letter images and text published by permission of Peter and Nejma Beard. Licensed for use under the Creative Commons Attribution-Noncommercial 3.0 Unported License. ©2010

*Beta Edition, 2010
*First Edition, 2011

Image Processing
Image processing relies on using tailored mathematical algorithms in order to manipulate and enhance data captured through the multispectral imaging process. Examples of simple manipulation include retouching, color correction, noise reduction, and changing image contrast. Processing techniques can also take a variety of complex forms. In the case of palimpsests, for instance, imaging scientists can create an algorithm to peel back the prominent "overtext" (the uppermost layer of text) in order to reveal the "undertext" (the underlying text), which is often much more difficult, if not impossible, to read.
Figures 4.1 and 4.2. Imaging scientists Roger L. Easton, Jr. (left) and Keith Knox (right) inspect Livingstone's letter after the multispectral imaging session.
The processing of Livingstone’s letter to Waller involved a high degree of collaboration between Project Director Adrian S. Wisnicki and the imaging scientists. After the letter was imaged, Wisnicki reviewed the images of each leaf and marked several regions of interests (ROIs). He then submitted the marked-up images to the imaging team alongside questions outlining objectives for potential processing. The questions related to textual issues, such as bleedthrough and illegible handwriting, as well as physical qualities (water stains, wax residue, paper creases). 
In response, the imaging scientists used several techniques to enhance the images of the letter, from applying the standard pseudocolor processing to the raking images, to using a more complex multiband method that sought to separate out the different texts, stains, etc. (for more on the technical terms and the processed images produced, see Note on the Images). Alongside such processing, the team also evaluated the raw spectral images of the letter and provided a series of imaging recommendations that will guide future work on Livingstone’s 1870-71 field diary (see Introduction).
Data Management