Detection and information theoretic measures for quantifying the distinguishability between multimedia operator chains

Despite the large number of contributions on forensics in the recent years, there is still a lack of fundamental limits on how easily two signal processing operators (or operator chains) can be distinguished. We take a first step in this direction by proposing the use of some detection and information theoretic measures that are suitable for assessing those fundamental limits. The optimality and the links between those measures are discussed; they are used for quantifying the distinguishability between different operator chains, considering the different prior knowledge that could be available at the forensics analyst. Although this work is mainly a theoretical motivation to the use of those measures in forensic applications, its particularization to three practical scenarios is illustrated.