Title :
Block convergence in repeated transform coding: JPEG-100 forensics, carbon dating, and tamper detection
Author :
ShiYue Lai ; Bohme, Rainer
Author_Institution :
Dept. of Inf. Syst., Univ. of Munster, Munster, Germany
Abstract :
Repeated rounding of sample blocks in alternating domains creates complex convergence paths. We study convergence and block stability for JPEG images compressed with quality factor 100 and derive methods to detect such compression in grayscale bitmap images, to estimate the number of recompressions, to identify the DCT implementation used for compression, and to uncover local tampering if image parts have been compressed with JPEG-100 at least once.
Keywords :
Q-factor; convergence; data compression; discrete cosine transforms; image coding; DCT implementation; JPEG images; JPEG-100; JPEG-100 forensics; block convergence; block stability; carbon dating; convergence stability; grayscale bitmap images; image recompressions; local tampering; quality factor; repeated transform coding; tamper detection; Carbon; Convergence; Discrete cosine transforms; Forensics; Image coding; Quantization (signal); Transform coding;
Conference_Titel :
Acoustics, Speech and Signal Processing (ICASSP), 2013 IEEE International Conference on
Conference_Location :
Vancouver, BC
DOI :
10.1109/ICASSP.2013.6638214
