BIB-VERSION:: CS-TR-v2.0
ID:: ncstrl.dartmouthcs//TR2004-515
ENTRY:: August 31, 2004
ORGANIZATION:: Dartmouth College, Computer Science
TITLE:: Exposing Digital Forgeries by Detecting Duplicated Image Regions 
TYPE:: Technical Report (paper)
REVISION:: 1
AUTHOR:: Popescu, Alin C.
AUTHOR:: Farid, Hany
DATE:: August 2004
RETRIEVAL:: For a paper copy, email <reports@cs.dartmouth.edu>
RETRIEVAL:: For a paper copy, write to
       Technical Report Librarian
       Department of Computer Science
       Dartmouth College
       6211 Sudikoff Laboratory
       Hanover, NH 03755-3510
       USA
RETRIEVAL:: PDF at http://www.cs.dartmouth.edu/reports/TR2004-515.pdf
ABSTRACT:: 
We describe an efficient technique that automatically detects
duplicated regions in a digital image. This technique works by first
applying a principal component analysis to small fixed-size image
blocks to yield a reduced dimension representation. This
representation is robust to minor variations in the image due to
additive noise or lossy compression. Duplicated regions are then
detected by lexicographically sorting all of the image blocks. We show
the efficacy of this technique on credible forgeries, and quantify its
robustness and sensitivity to additive noise and lossy JPEG
compression.
END:: ncstrl.dartmouthcs//TR2004-515