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A trio of scholars has recently explained how an electronic camera can be used to read otherwise unreadable ancient inscriptions. To enhance vague images on ancient manuscripts, this team of scholars used an electronic camera and image-processing techniques developed for space photography at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory administered by the California Institute of Technology.
An electronic camera does not use photographic film. Only in the final stage of presentation is the information translated into visual form. Basically, the camera electronically measures the brightness of a great many points (or pixels) in its field of vision. Three to five pixels are usually sufficient to measure the width of a pen stroke. The electronic camera provides what scientists call a digital image—that is, the presentation of a picture in a numerical format. Each pixel is assigned a number in accordance with its brightness. Once a picture is recorded in digital form, it can be manipulated in various ways, with or without a computer, to enhance its image. After enhancement the digital image can be transformed into a visual image.
The authors give a short history of efforts to recover obscure ancient writings. When parchment was scarce, manuscripts were often scraped and a new text written on the scraped parchment, creating palimpsests. Some of the most important texts of antiquity have been transmitted as the underwriting of palimpsests. At first, scholars attempted to enhance faded or erased manuscripts by chemical techniques, which adversely affected the parchment. Later, ultraviolet, infrared and x-ray photography were used. But when these now widely available and inexpensive methods fail, electronic photography and image-processing techniques may solve the problem.
Once the digital image is stored, it can be processed in a variety of ways. For example, the contrast between light and dark areas can be enhanced—a technique known as contrast-stretching.
The problem with simple contrast-stretching, however, is that as the pen strokes are darkened, so is the background shading, obscuring the local contrast of the pen stroke against its background. The problem can be remedied by spatial filtering, which is a process that modifies the brightness of each pixel in accordance with the average brightness of its neighboring pixels.
Interestingly enough, electronic photography (and the accompanying enhancement potential) can be used on the original manuscript or on a conventional photographic copy of the manuscript. It can also be used in combination with ultraviolet, infrared and x-ray photographs.
The authors do not discuss whether these advanced techniques can be used on inscriptions written on broken pieces of pottery (ostraca), but there would seem to be no reason why they would not work on pottery as well as parchment. We wonder what additional information might still be obscured on the ostraca from Samaria, Lachish and Arad, and what other religious inscriptions may still be found on the potsherds recently uncovered in the northern Sinai by Ze’ev Meshel (“Did Yahweh Have a Consort?” BAR 05:02). Perhaps these new electronic techniques will disclose messages scholars never suspected were there.
A trio of scholars has recently explained how an electronic camera can be used to read otherwise unreadable ancient inscriptions.a To enhance vague images on ancient manuscripts, this team of scholars used an electronic camera and image-processing techniques developed for space photography at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory administered by the California Institute of Technology. An electronic camera does not use photographic film. Only in the final stage of presentation is the information translated into visual form. Basically, the camera electronically measures the brightness of a great many points (or pixels) in its field […]
