ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 May 1992
Page Count: 11

Additional Applications of Digital Image Processing to Forensic Document Examinations
Behnen, AP
Questioned document examiner and questioned document examiner, U.S. Army Crime Laboratory—CONUS, GA

Nelson, LK
Questioned document examiner and questioned document examiner, U.S. Army Crime Laboratory—CONUS, GA

(Received 25 July 1991; accepted 15 October 1991)

Abstract

Two experimental applications of digital image processing to the examination of questioned documents are evaluated. First is a comparison of digital image processing, electrostatic detection apparatus (ESDA) processing, side lighting, and photography in the decipherment of indented writing. Best results are achieved by first utilizing the ESDA, then digitally enhancing the ESDA lift using a high-pass sharpening filter. The second application is the use of image processing equipment to make fracture match comparisons to associate carbon film typewriter ribbons with questioned typescript. Split-screen images and image overlays are found to be very effective techniques for this kind of examination.

Wenderoth [1] and Baier et al. [2] have reported on image processing as it relates to questioned document examination.

Keywords:
questioned documents, digital image processing, electrostatic detection apparatus (ESDA), image enhancement, photography, side-lighting, questioned document, carbon film ribbon, edge fracture match

Paper ID: JFS11991J
DOI: 10.1520/JFS11991J
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