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NCJ Number
216329
Journal
Law Enforcement Technology Volume: 33 Issue: 10 Dated: October 2006 Pages: 80,82-84,86,89
Author(s)
Troy Lyons
Date Published
October 2006
Length
8 pages
Annotation
This article describes the procedures, software specifications, and printer specifications required to authenticate, process, and enhance images recorded by digital cameras as evidence in police investigations.
Abstract
Because digital images have the potential of being altered through various computerized manipulations, authentication of the image as an accurate record of an actual event, object, or scene may be required for a court to admit it as evidence. The court may require software authentication. This article describes in detail the authentication process for digital images used by the York County/City of Poquoson Sheriff's Office (Virginia). It is a multistep, software-based process. The article also distinguishes between image "processing" and image "enhancement." "Processing" of digital images is limited to the production of an image that is adjusted according to size, resolution, color, brightness, and contrast. The computer software that can be used to perform these functions is described. It is essential that the software be able to keep a history log file. "Enhancing" a digital image involves improving its quality without changing the content of the record itself. Enhancement of an image usually involves improving the clarity of fingerprint or impression evidence in order to facilitate the matching process. This article describes software suitable for these tasks, as well as the specifications of printers that are recommended for producing digital crime scene images.