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Digital Rectification and Resizing Correction of Photographic Bite Mark Evidence

NCJ Number
218794
Author(s)
C. Michael Bowers; Raymond J. Johansen
Date Published
July 2001
Length
5 pages
Annotation
This article describes the digital rectification and resizing correction of photographic bite mark evidence from a 1973 homicide case that was prosecuted in 2000.
Abstract
Due to photographic distortion, when photographs are re-sized to be used as evidence the image must be corrected to show the true shape and dimension of the bite mark. The methods described here use the digital editing program Adobe Photoshop 5.5, a desktop computer, and a flatbed scanner. The method involved scanning the original photograph at 300 dpi on a Microtek Scanmaker V6USL flatbed scanner and importing the image into the Adobe Photoshop 5.5 editing program. The original image was then adjusted for contrast and rotation and was cropped. The digital rectification was made by measuring the sides and internal angles of the G scale using Photoshop. Portions of the G scale were then returned to their original shape using the Photoshop distort function. The step-by-step process is enumerated. Next, the dimensions of the G scale were used to re-size the image to life-sized. A brief description of the process is provided. The methods described here are useful with evidence photographs that contain a scale of known dimension. Figures, references