@TechReport{Dartmouth:TR2008-638,
  author = {Hany Farid},
  title = {{Digital Image Ballistics from JPEG Quantization: A Followup Study}},
  institution = {Dartmouth College, Computer Science},
  address = {Hanover, NH},
  number = {TR2008-638},
  year = {2008},
  month = {December},
  URL = {http://www.cs.dartmouth.edu/reports/TR2008-638.pdf},
  abstract = {
    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.
  }
}