NCJ Number
226901
Journal
Journal of Forensic Sciences Volume: 54 Issue: 3 Dated: May 2009 Pages: 639-641
Date Published
May 2009
Length
3 pages
Annotation
This study tested whether individual video source cameras could be identified by using a correlation coefficient of fixed pattern noise (FPN) in image sensors.
Abstract
The findings show that a specific CCD (charge-coupled device) module can be distinguished among five modules of the same brand by analyzing the normalized correlation coefficient of FPN. The coefficient changed slightly after 10 days; however, the change was generally small, such that the temporal change of the coefficient over several days is negligible for camera identification. In addition, a positive relationship was found between the correlation coefficients of the same modules and the number of frames that were used for image integration. Consequently, it is important to acquire as many frames as possible for precise video-camera identification. Future work will include video camera identification using FPN caused by photo-response nonuniformity in image sensors and development of a practical method for extracting FPN from images of natural scenes. Experiments on the temporal change of the correlation coefficients during several years must also be conducted. Five color CCD modules of the same brand of video camera were examined in the current research. Images were captured using a 12-bit monochrome video capture board and stored in a personal computer. For each module, 100 frames were captured. They were integrated in order to obtain FPN. 3 figures and 12 references