Video Frame Comparisons in Digital Video Authenticity Analyses

The scientific authentication of digital video-audio recordings involves the examination of both the visual and acoustic information through a number of analysis steps. One step in this pro- tocol is determining whether any of the individual images are identical to any other images within the same digital recording. Additionally, in some examinations, it is necessary to identify nonmatching pixels from nearly identical images. These duplicate, or nearly duplicate images, could be indicative of editing, an irregularity of a specific recording device, or just identically captured and processed images. In this paper, three questions involving video frame comparisons are addressed: (1) Does a specif ic, commonly available, consumer-quality camcorder produce any identical images with a static visual view in standard and high definition modes? (2) Are there accurate methodologies for determining whether two recorded digital images are identical? (3) What digital analysis procedures are available for compar- ing two nearly identical images? These questions are answered with the analysis of more than 147,100 frames from a consumer camcorder using digital data analyses and Photoshop routines.