Scattering codes to implement short 3-secure fingerprinting forcopyright protection

Collusion attacks are a major issue in fingerprinting schemes for copyright protection. A new class of codes, called scattering codes, is presented which can be used to control colluders' strategy in collusions of size up to 3. Scattering codes can be combined with dual Hamming codes to obtain 3-secure fingerprinting codes much shorter than those resulting from Boneh-Shaw's general construction     

Guest Editors' Introduction: Human-Centered Computing--Toward a Human Revolution

Human-centered computing studies the design, development, and deployment of mixed-initiative human-computer systems. HCC is emerging from the convergence of multiple disciplines that are concerned both with understanding human beings and with the design of computational artifacts.     

Distance learning for similarity estimation

In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized variants according to the Maximum Likelihood theory. These measures can provide a more accurate feature model than the classical Euclidean and Manhattan distances. We also find that the feature elements are often from heterogeneous sources that may have different influence on similarity estimation. Therefore, the assumption of single isotropic distribution model is often inappropriate. To alleviate this problem, we use a boosted distance measure framework that finds multiple distance measures which fit the distribution of selected feature elements best for accurate similarity estimation. The new distance measures for similarity estimation are tested on two applications: stereo matching and motion tracking in video sequences. The performance of boosted distance measure is further evaluated on several benchmark data sets from the UCI repository and two image retrieval applications. In all the experiments, robust results are obtained based on the proposed methods.     

Personalization in multimedia retrieval: A survey

With the explosive broadcast of multimedia (text documents, image, video etc.) in our life, how to annotate, search, index, browse and relate various forms of information efficiently becomes more and more important. Combining these challenges by relating them to user preference and customization only complicates the matter further. The goal of this survey is to give an overview of the current situation in the branches of research that are involved in annotation, relation and presentation to a user by preference. This paper will present some current models and techniques being researched to model ontology, preference, context, and presentation and bring them together in a chain of ideas that leads from raw uninformed data to an actual usable user interface that adapts with user preference and customization.     

Special Issue on Generating Realistic Visual Data of Human Behavior

International Journal of Computer Vision -     

Application of facial reduction to H ∞ state feedback control problem

One often encounters numerical difficulties in solving linear matrix inequality (LMI) problems obtained from H _∞ control problems. For semidefinite programming (SDP) relaxations for combinatorial problems, it is known that when either an SDP relaxation problem or its dual is not strongly feasible, one may encounter such numerical difficulties. We discuss necessary and sufficient conditions to be not strongly feasible for an LMI problem obtained from H _∞ state feedback control problems and its dual. Moreover, we interpret the conditions in terms of control theory. In this analysis, facial reduction, which was proposed by Borwein and Wolkowicz, plays an important role. We show that the dual of the LMI problem is not strongly feasible if and only if there exist invariant zeros in the closed left-half plane in the system, and present a remedy to remove the numerical difficulty with the null vectors associated with invariant zeros in the closed left-half plane. Numerical results show that the numerical stability is improved by applying it.     

Reduction of H∞ state feedback control problems for the MIMO servo systems

We deal with H_∞ state feedback control problem for the multi‐input‐multi‐output (MIMO) servo system and discuss the advantages of the facial reduction (FR) to the resulting linear matrix inequality (LMI) problems. In fact, as far as our usual setting, the dual of the LMI problem is not strictly feasible because the generalized plant has always stable invariant zeros. Thus FR is available to such LMI problems, and we can reduce and simplify the original LMI problem to a smaller‐size LMI problem. As a result, we observe that the numerical performance of the SDP solvers is improved. Also, as a by‐product, we obtain the best performance index of the reduced LMI problem with a closed‐form expression. This helps the H_∞ performance limitation analysis. Another contribution is to reveal that the resulting LMI problem obtained from H_∞ control problem has a finite optimal value, but no optimal solutions under an additional assumption. This is also confirmed in the numerical experiment of this paper. FR also plays an essential role in this analysis.     

Critique to Burmester and Le attack to Sebe/spl acute/ and Domingo-Ferrer fingerprinting scheme

Burmester and Le (2004) claimed in a very recent Letter that the 3-secure fingerprinting scheme proposed by Sebe/spl acute/ and Domingo-Ferrer (2002) was vulnerable to an attack in which a collusion of any three buyers could frame an innocent buyer. The authors show that the assumptions made by Burmester and Le in their attack cannot be made in practice.