NCJ Number
218676
Date Published
July 2005
Length
6 pages
Annotation
This paper briefly describes best practices for documenting image enhancement used in the criminal justice system.
Abstract
Two fundamental end uses for images encountered in the legal system include Category One images which are used to demonstrate what the photographer or recording device witnessed but are not analyzed by subject matter experts and Category Two images which are used for scientific analysis. Basic image enhancement techniques are those used to improve the overall appearance of the image and include, but are not limited to, resizing, cropping, image rotation and/or inversion, and white balance. Advanced image enhancement techniques are applied to images to extract information. The techniques include, but are not limited to, frame averaging, deblur, image restoration, and perspective control and/or geometric correction. When enhancing Category One images, one need only document the techniques with a standard operating procedure (SOP). When enhancing Category Two images, enhancement techniques should be documented in every case. Following these recommendations will help fulfill the requirements for the admissibility of images in a court of law. Image enhancement has been used in forensic application since the 1840s and an accepted practice in forensic science, regardless of whether it is performed in a traditional wet chemistry darkroom or in a laboratory. Accurate image enhancement techniques documentation is necessary to satisfy the legal requirements for introducing forensic images as evidence in a court of law. 1 reference, 1 appendix