A real-time color image processing system for forensic fiber investigations

During forensic fiber investigations a material is searched for single fibers transferred in connection to a crime. If fibers can be matched it is an indication of a connection between the crime scene and the material investigated or between persons. This paper describes an automated searching system based on color image analysis. The system is primarily developed for forensic textile fiber investigations but the approach is also suitable for other applications, e.g. paint flake and spermatozoa detection. The present system is applied in the initial, time-consuming stage of the investigation to identify single fiber fragments for subsequent investigation with more selective and powerful techniques. Subjects discussed include hardware and software constructions, practical usefulness, operator requirements and possible future developments. Brief reviews of color description and forensic fiber investigations are also given. The system is based on commonly available techniques, i.e. a CCD-camera, a motorized sample table and an IBM-compatible PC/AT with add-on boards for video frame digitalization and stepping motor control as the main parts. With the aid of the HSI-color system (Hue-Saturation-Intensity) and software optimization it is possible to operate the instrument at full video rate and fiber detection capability comparable to human investigators. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.