NCJ Number
218703
Date Published
October 2004
Length
2 pages
Annotation
This introductory comment by the chairperson of the Scientific Working Group on Imaging Technology (SWGIT) accompanied the distribution to North American law enforcement officials of the "Digital Imaging Procedure, Version 1.0," which was published by the United Kingdom's Police Scientific Development Branch for the purpose of addressing issues of digital image acquisition and integrity.
Abstract
The introductory statement notes that one of the most critical recommendations presented in the Digital Imaging Procedure, Version 1.0 is the concept of a master copy, which is the digital equivalent of an original film negative or video tape. A master copy represents either a bit-for-bit duplicate of original digital files or a digital copy of an analog recording that has been written to a compact disc or DVD-R. The master copy can be managed according to the same policies and procedures used to protect and preserve the integrity of an original film negative or video tape. Since it is difficult to conceal any manipulation when it is compared to the master file, a master copy is critical in protecting the integrity of digital image files. Another concept discussed in Digital Imaging Procedure, Version 1.0 is that all imaging devices (film, video, or digital still cameras) do not duplicate the reality recorded, but rather generate a visual representation that is conditioned by the many factors that influence the production of the image, including the type of camera used, the processing applied to the image, and the means by which the image is displayed. Agencies should be attentive to the development of policies and procedures that lead to the production of images that are of sufficient quality to achieve their objectives. SWGIT encourages agencies to incorporate the recommendations presented in the Digital Imaging Procedure, Version 1.0.