Authors: Jesse Kornblum (Defense Cyber Crime Institute, USA)
DFRWS USA 2008
The quantization tables used for JPEG compression can also be used to help separate images that have been processed by software from those that have not. This loose classification is sufficient to greatly reduce the number of images an examiner must consider during an investigation. As illicit imagery prosecutions depend on the authenticity of the images involved, this capability is an advantage for forensic examiners. This paper explains how quantization tables work, how they can be used for image source identification, and the implications for computer forensics.