NCJ Number
218710
Date Published
January 2003
Length
13 pages
Annotation
The Scientific Working Group on Imaging Technologies (SWGIT) presents recommendations and guidelines for the use of digital image processing in the criminal justice system, so as to ensure the successful introduction of forensic imagery as evidence in a court of law.
Abstract
The guidelines address digital image processing and related legal considerations in the following four categories: image enhancement, image restoration, image compression, and image analysis. Image enhancement is any process intended to improve the visual appearance of an image. Guidelines for image enhancement pertain to traditional enhancement techniques, nontraditional enhancement techniques, and considerations for the application of image enhancement techniques with respect to rules of evidence. The four legal tests applied to any forensic imagery introduced as evidence in court are its, reliability, reproducibility, security, and discovery. Image restoration is any process applied to an image that has been degraded by a known cause in order to partially or totally remove the effects of the degradation. Issues discussed in this category of image processing are restoration techniques and considerations for the application of image restoration techniques. Image compression refers to techniques that reduce the storage requirements for digital images by making image data files smaller. Guidelines and information in this category address compression processes and considerations for the application of image compression techniques. Quantitative image analysis refers to the process used to extract quantitative (measurable) data from an image, and cognitive image analysis is the process used to extract visual information from an image. The guidelines presented in this paper pertain only to quantitative analysis. The paper discusses quantitative image analysis techniques and considerations for the application of image analysis techniques. The paper concludes with guidelines for digital-image-processing standard operating procedures.