Multimedia Data

Following an introduction to the history of the invention of the quantum cascade (QC) laser and of the band-structure engineering advances that have led to laser action over most of the mid-infrared (IR) and part of the far-IR spectrum, the paper provides a comprehensive review of recent developments that will likely enable important advances in areas such as optical communications, ultrahigh resolution spectroscopy and applications to ultrahigh sensitivity gas-sensing systems. We discuss the experimental observation of the remarkably different frequency response of QC lasers compared to diode lasers, i.e., the absence of relaxation oscillations, their high-speed digital modulation, and results on mid-IR optical wireless communication links, which demonstrate the possibility of reliably transmitting complex multimedia data streams. Ultrashort pulse generation by gain switching and active and passive modelocking is subsequently discussed. Recent data on the linewidth of free-running QC lasers ( 150 kHz) and their frequency stabilization down to 10 kHz are presented. Experiments on the relative frequency stability ( 5 Hz) of two QC lasers locked to optical cavities are discussed. Finally, developments in metallic waveguides with surface plasmon modes, which have enabled extension of the operating wavelength to the far IR are reported. I N THIS paper, we concentrate on reviewing recent developments in quantum cascade (QC) laser research in the areas of high-speed modulation, optical wireless, ultrashort pulse and Manuscript

Structured audio representations are semantic and symbolic descriptions that are useful for ultralow-bit-rate transmission, flexible synthesis, and perceptually based manipulation and retrieval of sound. We present an overview of techniques for transmitting and synthesizing sound represented in structured format, and for creating structured representations from audio waveforms. We discuss applications for structured audio in virtual environments, music synthesis, gaming, content-based retrieval, interactive broadcast, and other multimedia contexts.

Digital watermarking was introduced at the end of the 20th century to provide means of enforcing copyright protection once the use and distribution of digital multimedia data have exploded. This technology has first been intensively investigated for still images and recent efforts have been put to exhibit unifying characteristics. On the other hand, the situation is rather different in the context of video watermarking, where unrelated articles are scattered throughout the literature. The purpose of this paper is consequently to give an in-depth overview of video watermarking and to point out that it is not only a simple extension of still images watermarking. New applications have to be considered, specific challenges have to be taken up and video-driven approaches have to be investigated. r

Les applications multimédias distribuées nécessitent des Qualités de Service (QoS) différentes suivant le type de média utilisé et les catégories de réseau de communication disponibles, chacun d'eux fournissant des qualités de Service variées. Cet article présente un nouveau protocole MMPOC-MN ayant pour objectif de combiner les deux aspects énoncés précédemment. Ce protocole repose sur les concepts d'ordre et de fiabilité partiels et a été spécialement conçu pour supporter des flux de données multimédias. Il permet de tirer parti des réseaux de communication disponibles en accordant la QoS requise par les flux multimédias à celle fournie par ces réseaux. Après avoir décrit l'architecture générale de MMPOC-MN, cet article s'intéressera au problème de la mise en oeuvre et du déploiement facile de ce protocole grâce au concept des « réseaux actifs ». L'implémentation et des mesures de performances de ce protocole seront également présentées dans cet article.

Security of information has become a major issue during the last decades. New algorithms based on chaotic maps were suggested for protection of different types of multimedia data, especially digital images and videos in this period. However, many of them fundamentally were flawed by a lack of robustness and security. For getting higher security and higher complexity, in the current paper, we introduce a new kind of symmetric key block cipher algorithm that is based on tripled chaotic maps. In this algorithm, the utilization of two coupling parameters, as well as the increased complexity of the cryptosystem, make a contribution to the development of cryptosystem with higher security. In order to increase the security of the proposed algorithm, the size of key space and the computational complexity of the coupling parameters should be increased as well. Both the theoretical and experimental results state that the proposed algorithm has many capabilities such as acceptable speed and complexity in the algorithm due to the existence of two coupling parameter and high security. Note that the ciphertext has a flat distribution and has the same size as the plaintext. Therefore, it is suitable for practical use in secure communications. *

An approach for knowledge assisted semantic analysis and annotation of video content, based on an ontology infrastructure is presented. Semantic concepts in the context of the examined domain are defined in an ontology, enriched with qualitative attributes of the semantic objects (e.g. color homogeneity), multimedia processing methods (color clustering, respectively), and numerical data or low-level features generated via training (e.g. color models, also defined in the ontology). Semantic Web technologies are used for knowledge representation in RDF/RDFS language. Rules in F-logic are defined to describe how tools for multimedia analysis should be applied according to different object attributes and low-level features, aiming at the detection of video objects corresponding to the semantic concepts defined in the ontology. This supports flexible and managed execution of various application and domain independent multimedia analysis tasks. This ontology-based approach provides the means of generating semantic metadata and as a consequence Semantic Web services and applications have a greater chance of discovering and exploiting the information and knowledge in multimedia data. The proposed approach is demonstrated in the Formula One and Football domains and shows promising results.

Computational biology unites biomedical research and high-performance computing and visualization. The topics in this special section will range from genome assembly to virtual reality support for surgery and from predicting gene and protein structure to combining multiple sources of biological data, as well as the general improvement of human health and health care.

Multimedia information access on the Internet creates a new paradigm for museum information and education service that complements conventional school programs. We designed and developed the Global Digital Museum to permit easy access to the cultural heritage ...

HyperText Markup Language (HTML) is a platform-independent method of identifying a document's structure and references. The Web is a distributed hypertext multimedia information service that has brought millions of non-academic and academic users to the Internet. In constrast to traditional GIS, multimedia Web GIS is not only able to collect, analyze and store data in traditional formats i.e. text, images and graphs but also audio, animations and video, using all the techniques, advantages and multimedia facilities of the Web. This paper explains multimedia data and the advantages of multimedia GIS (MMGIS) over traditional GIS. HTML plays a robust role in the development of the multimedia Web GIS. Through HTML our multimedia Web GIS can be viewed in three different categories. These are Static Web GIS, Dynamic Web GIS, and Active Web GIS. These three broad categories are also discussed

Data warehouses are dedicated to collecting heterogeneous and distributed data in order to perform decision analysis. Based on multidimensional model, OLAP commercial environments such as they are currently designed in traditional applications are used to provide means for the analysis of facts that are depicted by numeric data (e.g., sales depicted by amount or quantity sold). However, in numerous fields, like in medical or bioinformatics, multimedia data are used as valuable information in the decisional process. One of the problems when integrating multimedia data as facts in a multidimensional model is to deal with dimensions built on descriptors that can be obtained by various computation modes on raw multimedia data. Taking into account these computation modes makes possible the characterization of the data by various points of view depending on the user's profile, his best-practices, his level of expertise, and so on. We propose a new multidimensional model that integrates functional dimension versions allowing the descriptors of the multidimensional data to be computed by different functions. With this approach, the user is able to obtain and choose multiple points of view on the data he analyses. This model is used to develop an OLAP application for navigation into a hypercube integrating various functional dimension versions for the calculus of descriptors in a medical use case.

Digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data in a networked environment. It makes possible to tightly associate to a digital document a code allowing the identification of the data creator, owner, authorized consumer, and so on. In this paper a new watermarking algorithm for digital images is presented: the method, which operates in the frequency domain, embeds a pseudo-random sequence of real numbers in a selected set of DCT coefficients. After embedding, the watermark is adapted to the image by exploiting the masking characteristics of the human visual system, thus ensuring the watermark invisibility. By exploiting the statistical properties of the embedded sequence, the mark can be reliably extracted without resorting to the original uncorrupted image. Experimental results demonstrate that the watermark is robust to several signal processing techniques, including JPEG compression, low pass and median filtering, histogram equalization and stretching, dithering, addition of Gaussian noise, resizing, and multiple watermarking.

The recording performance of data-storage devices, in which write/read elements move relative to a storage medium to reliably store and retrieve information, depends on the capability of servo mechanisms to provide the necessary positioning accuracy. The desired characteristics of servo mechanisms for datastorage systems include robustness against variations of environmental parameters, high resolution, accuracy, stability, and fast response. This paper presents a comprehensive overview of advanced servo-control methods for data storage. The applications are to well-established recording technologies, including magnetic tape and magnetic disk systems as well as CD/DVD/Blue-Ray optical data-storage systems. Moreover, newer holographic and nearfield optical systems and the emerging probe-storage technology are also addressed. Emphasis is given to the potential exhibited by the technologies considered for achieving ultra-high storage capacity, as required by the exploding demand in data-storage capacity for archival systems and massive multimedia data storage.

Digital watermarking techniques have been proposed for copyright protection and authentication of multimedia data. In this paper, we propose a novel Chinese Remainder Theorem (CRT)-based technique for digital watermarking in the Discrete Cosine Transform (DCT) domain that is robust to several common attacks. We compared the performance of the proposed technique with recently proposed Singular Value Decomposition (SVD)based and spatial CRT-based watermarking schemes. Experimental results have shown that the proposed technique successfully makes the watermark perceptually invisible and has better robustness to common image manipulation techniques such as JPEG compression, brightening and sharpening effects compared to the spatial domain-based CRT scheme. The proposed scheme is able to achieve a Tamper Assessment Function (TAF) value of less than 10% when the watermarked image undergoes JPEG compression between a range of 50 to 70%, where as, the spatial CRT-based scheme produce TAF value of more than 35% and the SVD-based scheme produces TAF value between 10 to 40% depending on the host image, for the same range of compression. When the watermark capacity is doubled, the proposed technique is still able to maintain imperceptibility and low TAF values, for most of the attacks.

Mobile ad hoc networks (MANET) are becoming an integral part of the ubiquitous computing and communication environment, providing new infrastructure for multimedia applications such as video phone, multimedia-on-demand, and others. In order to access multimedia information in MANET, Quality of Service (QoS) needs to be considered, such as high success rate to access multimedia data, bounded end-to-end delay, and others. In this paper, we present a data accessibility service for a group of mobile users to access desired data with high success rate. This accessibility service is only possible if we utilize advanced data advertising, lookup and replication services, as well as a novel predictive location-based QoS routing protocol in an integrated fashion. Using cross-layer design, we illustrate how the QoS routing protocol assists data advertising, lookup and replication services to achieve high data access success rate. Simulation results have shown that our design is successful in a dynamic MANET.

One of the greatest challenges for computing today involves providing access to large volumes of distributed multimedia data. Mapping and personal navigation are among the most interesting applications involving this challenge, since they require access to static (such as street maps) and dynamic (such as traffic conditions) geospatial data. Such applications are currently the focus of much attention, considering that hardware is improving and wireless networks are becoming ubiquitous. Access to online maps is mainly done through proprietary and thematically limited geographic information services, such as Google Maps. A more interesting alternative for mobile applications is to use sources from spatial data infrastructures based on the Open Geospatial Consortium's standardized Web services, such as the Web Map Service (WMS). WMS, however, imposes a high communications overhead and power consumption to the mobile device, and has a limited scalability potential. This paper presents a proposal for the development of an SDI environment in which some of these challenges can be adequately met, from both a geoinformatics and a mobile computing perspective.

The distribution and retrieval of multimedia data over wireless networks have become widespread, thus creating the need for secure transmission of data over networks. However, one of the main problems with the secure transmission of digital data over wireless networks is that the errors that occur during transmission typically need to be resolved before decryption can begin. Because of the limited resources such as power and size of these wireless devices, hardware-efficient implementations of these operations are essential. This paper presents a joint hardware-efficient design for both encryption and channel coding that is optimized for low-resource requirements. We implemented the Rijndael Advance Encryption Standard (AES) algorithm and convolutional encoder for the encryption and encoder sub-unit, respectively. In order to decode the received digital data, we use the Viterbi decoder, which has been known to be suited for convolutional codes. Our design has a 70% reduction in the number of hardware resources for the encoding sub-unit through the block of XORs. The low-resource usage is achieved through an integrated architecture of the encoding units. Most of the hardware reduction was achieved in the AddRoundKey and the encoder sub-unit. Our system was implemented on a Xilinx Spartan 3 xc3s200FT256 using ISE foundation 8.1, and 13% of the slices were used for the Viterbi decoder with 674 bels. The maximum frequency was 55.872 MHz with a minimum period of 17.898 ns.

This paper presents an overview of what eXtensible Markup Language (XML) is and how it might be applied to the arching and sharing of qualitative multimedia data. It provides information about various current metadata schemas and initiatives based on XML which are primarily applied to textual data. An outline of the levels of metadata required for the fullest description multimedia qualitative data is proposed. Existing metadata standards are then evaluated in terms of their suitability for marking up multimedia data and recommendations are made for metadata schema synthesis and future development.

Security of information has become a major issue during the last decades. New algorithms based on chaotic maps were suggested for protection of different types of multimedia data, especially digital images and videos in this period. However, many of them fundamentally were flawed by a lack of robustness and security. For getting higher security and higher complexity, in the current paper, we introduce a new kind of symmetric key block cipher algorithm that is based on tripled chaotic maps. In this algorithm, the utilization of two coupling parameters, as well as the increased complexity of the cryptosystem, make a contribution to the development of cryptosystem with higher security. In order to increase the security of the proposed algorithm, the size of key space and the computational complexity of the coupling parameters should be increased as well. Both the theoretical and experimental results state that the proposed algorithm has many capabilities such as acceptable speed and complexity in the algorithm due to the existence of two coupling parameters and high security. Note that the ciphertext has a flat distribution and has the same size as the plaintext. Therefore, it is suitable for practical use in secure communications.

This paper presents an infrastructure and a prototype system for a manufacturing information system, which is distributed its nature and is able to store, index, manage, retrieve and present business data, inventory data, and manufacturing processes data. The system works with all kinds of information, such as continuous (i.e., stream oriented) data, production (e.g., decision support) data, legacy data, and multimedia data (say, drawings, pictures, audio signals, voice annotations, and video streams). A key criterion is support for content-based information retrieval across all application areas. The main objective is to provide support for automated information transactions. The prototype of our architecture uses JAVA, STEP (ISO 10303) standard, the Internet, and CORBA. A fully functional system, called Perspective, for retrieval of part and manufacturing process has been designed and implemented in a distributed environment. Among other capabilities, the system can retrieve a set of parts or manufacturing processes based on similarity to some desired criteria.

Much working time is spent in meetings and, as a consequence, meetings have become the subject of multidisciplinary research. Virtual Meeting Rooms (VMRs) are 3D virtual replicas of meeting rooms, where various modalities such as speech, gaze, distance, gestures and facial expressions can be controlled. This allows VMRs to be used to improve remote meeting participation, to visualize multimedia data and as an instrument for research into social interaction in meetings. This paper describes how these three uses can be realized in a VMR. We describe the process from observation through annotation to simulation and a model that describes the relations between the annotated features of verbal and non-verbal conversational behavior. As an example of social perception research in the VMR, we describe an experiment to assess human observers’ accuracy for head orientation.

Many indexing approaches for high-dimensional data points have evolved into very complex and hard to code algorithms. Sometimes this complexity is not matched by increase in performance. Motivated by these ideas, we take a step back and look at simpler approaches to indexing multimedia data. In this paper we propose a simple, (not simplistic) yet efficient indexing structure for high-dimensional data points of variable dimension, using dimension reduction. Our approach maps multidimensional points to a 1D line by computing their Euclidean Norm. In a second step we sort these using a B + -Tree on which we perform all subsequent operations. We exploit B + -Tree efficient indexed sequential search to develop simple, yet performant methods to implement point, range and nearest-neighbor queries.

Advances in information technology during the past decade have resulted in a proliferation of clinical information systems dedicated to dierent user groups and clinical functional areas. This, in turn, has created the need for hospital-wide management and integration of information, and has triggered major eorts towards the development of integrated hospital information systems as a building block of integrated regional healthcare networks. The diversity of hospital organizations, the complexity of clinical protocols and procedures, as well as the dierent preferences of various user groups make it extremely dicult for a single monolithic information system to eectively serve the needs of an entire healthcare organizational structure. Thus, information and telecommunications systems must primarily provide the infrastructure to support the eective integration of distributed and heterogeneous components, ensuring overall integrity in terms of functional and information interworking. This approach i.e., the integration of heterogeneous autonomous distributed systems, to developing and managing regional healthcare networks ensures the transfer and integration of consistent information between healthcare facilities, without imposing constraints on the operation of individual clinical units. This paper presents the results of an ongoing eort for the design and implementation of an architecture based on digital library technologies, for the provision of user-oriented telematic services in a regional healthcare network. Speci®cally, it addresses issues related to the provision of user-oriented services, transparent to the needs of dierent user groups and the requirements of speci®c tasks, based on: a) meta-information for the creation of an information infrastructure for the regional healthcare network which is, eectively, a multimedia distributed digital library, b) intelligent information retrieval strategies to selectively retrieve information from multimedia data, c) agent-based technologies for eective service delivery adapted to the current user needs and the task at hand, and d) middle-ware services that explicitly reveal not only the characteristics of the information sources, but also address the context of speci®c telematic services, through appropriate mediation mechanisms.

Multi-dimensional data structures are applied in many real index applications, i.e. data min- ing, indexing multimedia data, indexing non- structured text documents and so on. Many index structures and algorithms have been proposed. There are two major approaches to multi-dimensional indexing. These are, data structures to indexing metric and vec- tor spaces. The R-tree, R*-tree, and UB-tree are representatives of

This paper presents a unified framework for 3D shape retrieval. The method supports multimodal queries (2D images, sketches, 3D objects) by introducing a novel view-based approach able to handle the different types of multimedia data. More specifically, a set of 2D images (multi-views) are automatically generated from a 3D object, by taking views from uniformly distributed viewpoints. For each image, a set of 2D rotation-invariant shape descriptors is produced. The global shape similarity between two 3D models is achieved by applying a novel matching scheme, which effectively combines the information extracted from the multi-view representation. The experimental results prove that the proposed method demonstrates superior performance over other well-known state-of-the-art approaches.

Handheld mobile applications will become a driving economic factor both for further developments of telecommunication industry and for the acceptance of and public response to the EU initiative Galileo. This paper will briefly describe a prototype of a mobile multimedia tourism information system for outdoor activities and user oriented data management tools. Tourism information mostly is geographically related information and, therefore, many useful location aware applications can be offered. A PDA (Personal Digital Assistant) in connection with GPS function allows us to guide tourists to the desired sights or to hiking and biking tours of a tourism region. For a multimedia visualisation of tourism information pictures, sound, text and video elements were integrated in order to record the effectiveness of the mobile device. Cartographic illustrations using satellite images and digital maps are the base for an innovative presentation of tourism information in their spatial context. Mobile devices make possible an innovative presentation of tourism information and fulfil user desires for information provision.

This paper aims to describe a prototypal immersive virtual reality application, running in a Virtual Theater, that uses portable terminals to visualize multimedia data and to manage the interaction with 3D models regarding the survey and restoration of eight tombs along the ancient Rome's Appian Way. The starting point of our work is a 3D Web application where the user, interacting with VRML models of the tombs, can access to archaeological data: the baseline conditions before restoration, the various phases of restoration work and the final outcome . A Virtual Theater Technology enables the users to experience a more realistic fruition of the 3D models of the tombs and the use of portable terminals greatly increases the possibilities of interaction in virtual environments, maintaining also the capability to access via Internet all the multimedia archaeological data developed for the previous web application. Moreover the application is designed in order to enable peer-to-peer collaboration among users who can share data and interactions during their virtual experience.

Managing multimedia data requires more than collecting the data into storage archives and delivering it via networks to homes or offices. We survey technologies and applications for video-content analysis and retrieval. We also give specific examples.

This research was partially supported by the AIIS Inc., NY, USA, the Applied R&D Centers of the City University of Hong Kong (under grants no. 9410011 and no. 9620004), and the National Natural Science Foundation of China (under grant no. 60202002). Shujun Li and ...

The compressed sensing (CS) paradigm unifies sensing and compression of sparse signals in a simple linear measurement step. Reconstruction of the signal from the CS measurements relies on the knowledge of the measurement matrix used for sensing. Generation of the pseudo-random sensing matrix utilizing a cryptographic key, offers a natural method for encrypting the signal during CS. This CS based encryption has the inherent advantage that encryption occurs implicitly in the sensing process -without requiring additional computation. Additionally, the robustness of recovery from compressed sensing, allows a new form of "robust encryption" for multimedia data, wherein the signal is recoverable with high fidelity despite the introduction of additive noise in the encrypted data.

A complete tool chain starting with stereo photogrammetry based digitization of artefacts, their refinement, collection and management with other multimedia data, and visualization using virtual and augmented reality is presented. Our system provides a one-stop-solution for museums to create, manage and present both content and context for virtual exhibitions. Interoperability and standards are also key features of our system allowing both small and large museums to build a bespoke system suited to their needs.

Web accessed multimedia applications have been widely adopted under enhanced requirements for fast searching, browsing and retrieval. Efficient multimedia data content description is a neccesary and critical issue towards which several solutions have been proposed. In the present paper, we focus on the MPEG-7 standard as an efficient multimedia content description tool. MPEG-7 is a newly introduced standard from the MPEG commitee and a brief description of the standard and its components is given here. MPEG-7 Language-Schema as used towards efficient Audio/Visual content description is discussed more extensively. As decided by the MPEG-7 committee it the Description Definition Language (DDL) of the standard should be based on the XML Schema. The several extensions to this schema, necessary for satisfying the requirements of MPEG-7 are discussed, while other functionalities of the schema which seem not necessary under current specifications are also commented.

Background: The medical curriculum has changed with the adoption of the student-centered learning paradigm. Clinical reasoning learning (CRL) is used in order to develop and improve students' clinical reasoning and problem-solving skills. Purpose: We have observed that, in complement to traditional CRL sessions, students commonly consult resources available on the internet. Based on this observation, our objective is to create computer tools to coordinate CRL sessions at distance, integrating these electronic resources at every step of the reasoning process. Material and methods: In order to create the system, we elaborated an objectoriented model of a computer-supported collaborative learning environment. The proposed system includes a local web-server to store electronic resources and a relational database to store their electronic addresses (urls ). JAVA TM was used as the programming language. Results: We developed a set of cooperative platformindependent tools. This environment includes a communication tool. Multimedia data exchange is possible. Information is shared thanks to an electronic notepad and whiteboard tools. Perspectives: This learning environment will be integrated in the French Virtual Medical University project, and is intended to be used for undergraduate, internships, residency or continuing medical education.

This paper reviews 60-GHz radio-over-fiber systems employing optical frequency multiplication and adaptive OFDM signals with multi-level modulation formats to achieve an ultra-high data rate of up to 32.65 Gbps within the 7-GHz license-free band.

Multimedia Information Retrieval is currently a hot research topic due the popularity of the World Wide Web and the huge amount of multimedia data available. There exists an increasing interest to design and develop new methods and techniques to represent and classify this kind of information. Among the different sources of multimedia information currently available, we have decided to work with music audio files. Three different music representations (binary code, wave information, and SAX) have been used to study how the selection of a particular representation could affect a clustering process based on a set of similarity clusters. Two different algorithms (a hierarchical clustering method based on the quartet tree method and a genetic algorithm) have been applied to automatically perform the clustering. A compression distance, the Normalized Compression Distance (NCD), has been used to generate the similarities among the music files. This distance is parameter-free and widely applicable so we can use it directly with different formats and representations. The paper shows some experimental results using these representations and compares the behavior of both clustering methods.

In their arms race against developers of spam filters, spammers have recently introduced the image spam trick to make the analysis of emails' body text ineffective. It consists in embedding the spam message into an attached image, which is often randomly modified to evade signature-based detection, and obfuscated to prevent text recognition by OCR tools. Detecting image spam turns out to be an interesting instance of the problem of content-based filtering of multimedia data in adversarial environments, which is gaining increasing relevance in several applications and media. In this paper we give a comprehensive survey and categorisation of computer vision and pattern recognition techniques proposed so far against image spam, and make an experimental analysis and comparison of some of them on real, publicly available data sets.

Recent advances in technology have made tremendous amounts of multimedia information available to the general population. An efficient way of dealing with this new development is to develop browsing tools that distill multimedia data as information oriented summaries. Such an approach will not only suit resource poor environments such as wireless and mobile, but also enhance browsing on the wired side for applications like digital libraries and repositories. Automatic summarization and indexing techniques will give users an opportunity to browse and select multimedia document of their choice for complete viewing later. In this paper, we present a technique by which we can automatically gather the frames of interest in a video for purposes of summarization. Our proposed technique is based on using Delaunay Triangulation for clustering the frames in videos. We represent the frame contents as multi-dimensional point data and use Delaunay Triangulation for clustering them. We propose a novel video summarization technique by using Delaunay clusters that generates good quality summaries with fewer frames and less redundancy when compared to other schemes. In contrast to many of the other clustering techniques, the Delaunay clustering algorithm is fully automatic with no user specified parameters and is well suited for batch processing. We demonstrate these and other desirable properties of the proposed algorithm by testing it on a collection of videos from Open Video Project. We provide a meaningful comparison between results of the proposed summarization technique with Open Video storyboard and K-means clustering. We evaluate the results in terms of metrics that measure the content representational value of the proposed technique.

This paper describes a unified data model that represents multimedia, timeline, and simulation data utilizing a single set of related data modeling constructs. A uniform model for multimedia types structures image, sound, video, and long text data in a consistent way, giving multimedia schemas and queries a degree of data independence even for these complex data types. Information that possesses an intrinsic temporal element can all be represented using a construct called a stream. Streams can be aggregated into parallel multistreams, thus providing a structure for viewing multiple sets of time-based information. The unified stream construct permits real-time measurements, numerical simulation data, and visualizations of that data to be aggregated and manipulated using the same set of operators. Prototypes based on the model have been implemented for two medical application domains: thoracic oncology and thermal ablation therapy of brain tumors. Sample schemas, queries, and screenshots from these domains are provided. Finally, a set of examples is included for an accompanying visual query language discussed in detail in another document.

Current software systems contain increasingly more elements that have not usually been considered in software engineering research and studies. Source artifacts, understood as the source components needed to obtain a binary, ready to use version of a program, comprise in many systems more than just the elements written in a programming language (source code). Especially when we move apart from systems-programming and enter the realm of end-user applications, we find files for documentation, interface specifications, internationalization and localization modules and multimedia data. All of them are source artifacts in the sense that developers work directly with them, and that applications are built automatically using them as input. This paper discusses the differences and relationships between source code (usually written in a programming language) and these other files, by analyzing the KDE software versioning repository (with about 6,800,000 commits and 450,000 files). A comprehensive study of those files, and their evolution in time, is performed, looking for patterns and trying to infer from them the related behaviors of developers with different profiles, from where we conclude that studying those 'other' source artifacts can provide a great deal of insight on a software system.

The security of multimedia data transmitted over wireless networks is of increased interest. Encryption mechanisms securely transmit multimedia data over insecure networks. A major issue that has received very little attention so far is that the very same properties that gives ciphers (encryption mechanisms) their cryptographic strength make them sensitive to channel errors as well. In addition, this would enhance the error propagation inherent in compressed data. Therefore provision of security for multimedia transimission over wireless channel results in throughput loss. Nevertheless this lost throughput is traded for increased security. To our knowledge there has been no substantial effort to optimize this tradeoff. Opportunistic encryption proposed in this work is a way to optimize the tradeoff between security offered and the throughput lost due to a cipher. We show that opportunistic encryption methods that adapt to channel variations will lead to an overall increase in the system performance. Two broad scenarios are considered.

With advances in process technology, soft errors (SE) are becoming an increasingly critical design concern. Due to their large area and high density, caches are worst hit by soft errors. Although Error Correction Code based mechanisms protect the data in caches, they have high performance and power overheads. Since multimedia applications are increasingly being used in mission-critical embedded systems where both reliability and energy are a major concern, there is a definite need to improve reliability in embedded systems, without too much energy overhead. We observe that while a soft error in multimedia data may only result in a minor loss in QoS, a soft error in a variable that controls the execution flow of the program may be fatal. Consequently, we propose to partition the data space into failure critical and failure non-critical data, and provide a high-degree of soft error protection only to the failure critical data in Horizontally Partitioned Caches. Experimental results demonstrate that our selective data protection can achieve the failure rate close to that of a soft error protected cache system, while retaining the performance and energy consumption similar to those of a traditional cache system, with some degradation in QoS. For example, for conventional configuration as in Intel XScale, our approach achieves the same failure rate, while improving performance by 28% and reducing energy consumption by 29% in comparison with a soft error protected cache.

Treating electronic ink as first-class data -as opposed to simply a substitute for keyboard input -offers intriguing possibilities. The pen has well-known advantages in terms of portability and user acceptance, and ink is an extremely expressive medium that is inherently language-independent. A limitless range of representations are possible when writing/sketching. Moreover, ink shares important characteristics with other multimedia datatypes: it has a temporal component like speech, and a spatial component like images. However, adopting this approach raises some important issues with regard to storage and retrieval, as traditional techniques may no longer apply.