Saturday, February 4, 2012

Jack Reese: Advanced Photographic Techniques

image“We sometimes encounter damaged documents,” wrote Jack Reese, “that are difficult to read because they have faded due to exposure to water, mold, fire, excessive light, or natural fading.” In these situations, advanced photographic techniques can be used to produce legible images of the documents.

“For these challenging documents, the quality of digitization can often be greatly improved by performing multispectral analysis.” Reese is a systems architect at Ancestry.com. There he helped design, develop, and use the Ancestry DARC camera system. DARC stands for Document Restoration Camera.

Reese explained the system in his RootsTech session, “Using Advanced Photographic Techniques to Recover Content from Damaged Documents.” Different colors of light in the rainbow are different light frequencies. Beyond the visible frequencies in the rainbow are infrared and ultraviolet frequencies. DARC changes several properties. It can change the frequency of the lights shining on the document. It can use visible light, but it can also use infrared or ultraviolet. Likewise, it can change the frequencies of the light that are seen by the camera.

Here are examples of documents faded in visible light, but made readable when imaged in alternate spectrums.

Visible Light
Alternate spectrum light
Sample 1 in visible light Sample 1 in infrared light
Sample 2 in visible light Sample 2, probably IR light
Sample 3 in visible light Sample 3 in UV light

For more information, see “New Technology Saves Records” from Ancestry Magazine.

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