@conference {688, title = {Localization of Forgeries in MPEG-2 Video through GOP Size and DQ analysis}, booktitle = {IEEE International Workshop on Multimedia Signal Processing (MMSP)}, year = {2013}, pages = {494-499}, address = {Pula (Sardinia), Italy}, abstract = {

This work addresses forgery localization in MPEG-2 compressed videos. The proposed method is based on the analysis of Double Quantization (DQ) traces in frames that were encoded twice as intra (i.e., I-frames). \ Employing a state-of-the-art method, such frames are located in the video under analysis by estimating the size of the Group Of Pictures (GOP) that was used in the first compression; then, the DQ analysis is devised for the MPEG-2 encoding scheme and applied to frames that were intra-coded in both the first and second compression. In such a way, regions that were manipulated between the two encodings are detected. Compared to existing methods based on double quantization analysis, the proposed scheme makes forgery localization possible on a wider range of settings.

}, author = {Daniele Labartino and Tiziano Bianchi and Alessia De Rosa and Marco Fontani and David V{\'a}zquez-Pad{\'\i}n and Alessandro Piva and Mauro Barni} } @proceedings {717, title = {Near optimal detection of quantized signals and application to JPEG forensics}, journal = {2013 IEEE International Workshop on Information Forensics and Security (WIFS)}, year = {2013}, month = {11/2013}, pages = {168-173}, address = {Guangzhou, China}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6707813}, author = {Tiziano Bianchi and Alessandro Piva and Fernando P{\'e}rez-Gonz{\'a}lez} } @conference {662, title = {Detection of video double encoding with GOP size estimation}, booktitle = {IEEE International Workshop on Information Forensics and Security (WIFS)}, year = {2012}, month = {12/2012}, pages = {151-156}, publisher = {IEEE}, organization = {IEEE}, address = {Tenerife, Spain}, abstract = {

Video forensics is an emerging discipline, that aims at inferring information about the processing history undergone by a digital video in a blind fashion. In this work we introduce a new forensic footprint and, based on it, propose a method for detecting whether a video has been encoded twice; if this is the case, we also estimate the size of the Group Of Pictures (GOP) employed during the first encoding. As shown in the experiments, the footprint proves to be very robust even in realistic settings (i.e., when encoding is carried out using typical compression rates), that are rarely addressed by existing techniques.

}, author = {David V{\'a}zquez-Pad{\'\i}n and Marco Fontani and Tiziano Bianchi and Pedro Comesa{\~n}a and Alessandro Piva and Mauro Barni} }