%T Digital Image Ballistics from JPEG Quantization: A Followup Study
%A Hany Farid
%R Technical Report TR2008-638
%I Dartmouth College, Computer Science
%C Hanover, NH
%D December 2008
%U http://www.cs.dartmouth.edu/reports/TR2008-638.pdf
%X
 The lossy JPEG compression scheme employs a quantization table that
 controls the amount of compression achieved. Because different cameras
 typically employ different tables, a comparison of an image's
 quantization scheme to a database of known cameras affords a simple
 technique for confirming or denying an image's source.  This report
 describes the analysis of quantization tables extracted from 1,000,000
 images downloaded from Flickr.com.