A secure framework exploiting content guided and automated algorithms for real time video searching

This paper presents an architecture that allows End Users, via the services of Search Engines, to search, in a secure and efficient way, the video content belonging to Content Providers. The search can be accomplished with any searching scheme that the Search Engines wish to provide, as long as certain security constraints are met. However we propose specific algorithms that demonstrate an efficient way to search video data without sacrificing security effectiveness of the system. The search is completed without the End Users or Search Engines needing to purchase the premium content beforehand, and without the Content Providers needing to purchase the search technology. The business motivation of this technique is to assist End Users to purchase content best suiting their requirements—they are offered search results only, not actual content. The objective is to face the problem caused by the current segregation between content ownership and video processing technology ownership. To face this segregation, we present an architecture that guarantees security of Content Provider’s data and Search Engine’s technology and we also present two innovative algorithms that make real time video searching a feasible process. Particularly these algorithms (a) organize video content into a graph based hierarchical structure and (b) perform content guided, non interactive and real time search by exploiting the graph based video structures. The proposed algorithms are incorporated in the presented architecture under the given security constraints. Experimental results and comparisons with conventional techniques are presented to demonstrate the outperformance of the proposed algorithms.

Malware-Propagative Mobile Ad Hoc Networks: Asymptotic Behavior Analysis

In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyzed. Considering the Susceptible-Infected-Susceptible （SIS） node infection paradigm we propose a probabilistic model, on the basis of the theory of closed queuing networks, that aims at describing the aggregated behavior of the system when attacked by malicious nodes. Because of its nature, the model is also able to deal more effectively with the stochastic behavior of attackers and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative large scale ad hoc networking environments. Using the Norton equivalent of the closed queuing network, we obtain analytical results for its steady state behavior, which in turn is used for identifying the critical parameters affecting the operation of the network. Finally, through modeling and simulation, some additional numerical results are obtained with respect to the behavior of the system when multiple attackers are present, and regarding the time-dependent evolution and impact of an attack.     

Application of Compact Schemes to Large Eddy Simulation of Turbulent Jets

We present 3-D large eddy simulation (LES) results for a turbulent Mach 0.9 isothermal round jet at a Reynolds number of 100,000 (based on jet nozzle exit conditions and nozzle diameter). Our LES code is part of a Computational Aeroacoustics (CAA) methodology that couples surface integral acoustics techniques such as Kirchhoff's method and the Ffowcs Williams– Hawkings method with LES for the far field noise estimation of turbulent jets. The LES code employs high-order accurate compact differencing together with implicit spatial filtering and state-of-the-art non-reflecting boundary conditions. A localized dynamic Smagorinsky subgrid-scale (SGS) model is used for representing the effects of the unresolved scales on the resolved scales. A computational grid consisting of 12 million points was used in the present simulation. Mean flow results obtained in our simulation are found to be in very good agreement with the available experimental data of jets at similar flow conditions. Furthermore, the near field data provided by the LES is coupled with the Ffowcs Williams–Hawkings method to compute the far field noise. Far field aeroacoustics results are also presented and comparisons are made with experimental measurements of jets at similar flow conditions. The aeroacoustics results are encouraging and suggest further investigation of the effects of inflow conditions on the jet acoustic field.     

Color image denoising using evolutionary computation

Noise suppression in multichannel data sets, such as color images, has drawn much attention in the last few years. An issue of paramount importance in designing color image filters is the determination of the coefficients that should be used to weight the inputs to the filter. In this study, we propose an evolutionary computation‐based approach to select and optimize the coefficients in the class of weighted vector directional filters. Using a genetic algorithm, we were able to adapt the filter weights to match varying image and noise characteristics. Extended experimentation with realistic image processing applications, including television image enhancement and virtual restoration of artworks, indicates that the proposed filters are capable of removing noise while preserving chromaticity information, edges, and fine details, as well as structural image content. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 236–251, 2005     

Human action annotation,modeling and analysis based on implicit user interaction

This paper proposes an integrated framework for analyzing human actions in video streams. Despite most current approaches that are just based on automatic spatiotemporal analysis of sequences, the proposed method introduces the implicit user-in-the-loop concept for dynamically mining semantics and annotating video streams. This work sets a new and ambitious goal: to recognize, model and properly use “average user’s” selections, preferences and perception, for dynamically extracting content semantics. The proposed approach is expected to add significant value to hundreds of billions of non-annotated or inadequately annotated video streams existing in the Web, file servers, databases etc. Furthermore expert annotators can gain important knowledge relevant to user preferences, selections, styles of searching and perception.     

Reversible Interpolation of Vectorial Images by an Anisotropic Diffusion-Projection PDE

In this paper, a nonlinear model for the interpolation of vector-valued images is proposed. This model is based on an anisotropic diffusion PDE and performs an interpolation that is reversible. The interpolation solution is restricted to the subspace of functions that can recover the discrete input image, after an appropriate smoothing and sampling. The proposed nonlinear diffusion flow lies on this subspace while its strength and anisotropy adapt to the local variations and geometry of image structures. The derived method effectively reconstructs the real image structures and yields a satisfactory interpolation result. Compared to classic and other existing PDE-based interpolation methods, our proposed method seems to increase the accuracy of the result and to reduce the undesirable artifacts, such as blurring, ringing, block effects and edge distortion. We present extensive experimental results that demonstrate the potential of the method as applied to graylevel and color images. The authors acknowledge the financial support of the Future and Emerging Technologies (FET) programme ‘ASPI’ within the Sixth Framework Programme for Research of the European Commission, under FET-Open contract No. 021324.     

Semi-supervised vision-based maritime surveillance system using fused visual attention maps

This paper presents a vision-based system for maritime surveillance, using moving PTZ cameras. The proposed methodology fuses a visual attention method that exploits low-level image features appropriately selected for maritime environment, with appropriate tracker, without making any assumptions about environmental or visual conditions. The offline initialization is based on large graph semi-supervised technique. System’s performance was evaluated with videos from cameras placed at Limassol port and Venetian port of Chania. Results suggest high detection ability, despite dynamically changing visual conditions and different kinds of vessels, all in real time.     

A segmentation-free word spotting method for historical printed documents

In this paper, a two-step segmentation-free word spotting method for historical printed documents is presented. The first step involves a minimum distance matching between a query keyword image and a document page image using keypoint correspondences. In the second step of the method, the matched keypoints on the document image serve as indicators for creating candidate image areas. The query keyword image is matched against the candidate image areas in order to properly estimate the bounding boxes of the detected word instances. The method is evaluated using two datasets of different languages and is compared against segmentation-free state-of-the-art methods. The experimental results show that the proposed method outperforms significantly the competitive approaches.     

The effect of drying,pressure and processing time on the quality of liquid‐smoked trout (Salmo gairdnerii) fillets

A new fish smoking process was applied using a combination of liquid smoke and steaming at pressures up to 1 bar above atmospheric. Processing yield, sensory analysis, instrumental colour measurement, available lysine and polynuclear aromatic hydrocarbons (PAHs) were estimated. The losses due to processing were quite reasonable (20.05 ± 4.9% to 23.58 ± 3.9%) and slightly influenced by the process. The fillets processed at 2 bar steam pressure, for 30, 45 or 60 min and previously dried were assessed as highly acceptable regarding their firmness, colour, flavour and acceptability by panellists. The destruction of available lysine was not very high (21.1 ± 8.4%) and it was dependent upon the process. Depending on the method used, very low (0.63–3.2ng g⁻¹) amounts of PAHs were found and were also dependent upon the process. Copyright © 2005 Society of Chemical Industry