Rozprawy doktorskie na temat „Multimedia information objects”

Thesis (PhD)--Macquarie University, Division of Information and Communication Sciences, Department of Computing, 2008.<br>Bibliography: p. 144-153.<br>Introduction -- Background -- Overview of watermarking -- Natural language watermarking -- Software watermarking -- Semi-blind and reversible database watermarking -- Blind and reversible database watermarking -- Conclusion and future research -- Bibliography.<br>Digital watermarking has generated significant research and commercial interest in the past decade. The primary factors contributing to this surge are widespread use of the Internet with improved bandwidth and speed, regional copyright loopholes in terms of legislation; and seamless distribution of multimedia content due to peer-to-peer file-sharing applications. -- Digital watermarking addresses the issue of establishing ownership over mul-timedia content through embedding a watermark inside the object. Ideally, this watermark should be detectable and/or extractable, survive attacks such as digital reproduction and content-specific manipulations such as re-sizing in the case of images, and be invisible to the end-user so that the quality of the content is not degraded significantly. During detection or extraction, the only requirements should be the secret key and the watermarked multimedia object, and not the original un-marked object or the watermark inserted. Watermarking scheme that facilitate this requirement are categorized as blind. In recent times, reversibility of watermark has also become an important criterion. This is due to the fact that reversible watermarking schemes can provided security against secondary watermarking attacks by using backtracking algorithms to identify the rightful owner. A watermarking scheme is said to be reversible if the original unmarked object can be regenerated from the watermarked copy and the secret key.<br>This research covers three multimedia content types: natural language documents, software, and databases; and discusses the current watermarking scenario, challenges, and our contribution to the field. We have designed and implemented a natural language watermarking scheme that uses the redundancies in natural languages. As a result, it is robust against general attacks against text watermarks. It offers additional strength to the scheme by localizing the attack to the modified section and using error correction codes to detect the watermark. Our first contribution in software watermarking is identification and exploitation of weaknesses in branch-based software watermarking scheme proposed in [71] and the software watermarking algorithm we present is an improvised version of the existing watermarking schemes from [71]. Our scheme survives automated debugging attacks against which the current schemes are vulnerable, and is also secure against other software-specific attacks. We have proposed two database watermarking schemes that are both reversible and therefore resilient against secondary watermarking attacks. The first of these database watermarking schemes is semi-blind and requires the bits modified during the insertion algorithm to detect the watermark. The second scheme is an upgraded version that is blind and therefore does not require anything except a secret key and the watermarked relation. The watermark has a 89% probability of survival even when almost half of the data is manipulated. The watermarked data in this case is extremely useful from the users' perspective, since query results are preserved (i.e., the watermarked data gives the same results for a query as the nmarked data). -- The watermarking models we have proposed provide greater security against sophisticated attacks in different domains while providing sufficient watermark-carrying capacity at the same time. The false-positives are extremely low in all the models, thereby making accidental detection of watermark in a random object almost negligible. Reversibility has been facilitated in the later watermarking algorithms and is a solution to the secondary watermarking attacks. We shall address reversibility as a key issue in our future research, along with robustness, low false-positives and high capacity.<br>Mode of access: World Wide Web.<br>xxiv, 156 p. ill. (some col.)

We describe the design and implementation of a system for logic-based multimedia retrieval. As high-level logic for retrieval of hypermedia documents, we have developed a probabilistic object-oriented logic (POOL) which supports aggregated objects, different kinds of propositions (terms, classifications and attributes) and even rules as being contained in objects. Based on a probabilistic four-valued logic, POOL uses an implicit open world assumption, allows for closed world assumptions and is able to deal with inconsistent knowledge. POOL programs and queries are translated into probabilistic Datalog programs which can be interpreted by the HySpirit inference engine. For storing the multimedia data, we have developed a new basic IR engine which yields physical data abstraction. The overall architecture and the flexibility of each layer supports logic-based methods for multimedia information retrieval.

In this project a collaboration multimedia toolkit, JSCMT (Java Synchronized Collaborative Multimedia Toolkit) was developed which is intended to connect a group of people located in different geographical locations who are working on the same project.

by Chan Mei Shuen Polly.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.<br>Includes bibliographical references (leaves 67-70).<br>Abstract --- p.ii<br>Acknowledgement --- p.iii<br>Chapter 1 --- Introduction --- p.1<br>Chapter 1.1 --- Definitions --- p.3<br>Chapter 1.2 --- Thesis Overview --- p.5<br>Chapter 2 --- Background and Related Work --- p.6<br>Chapter 2.1 --- Feature-Based Index Structures --- p.6<br>Chapter 2.2 --- Distance Preserving Methods --- p.8<br>Chapter 2.3 --- Distance-Based Index Structures --- p.9<br>Chapter 2.3.1 --- The Vantage-Point Tree Method --- p.10<br>Chapter 3 --- The Problem of Distance Preserving Methods in Querying --- p.12<br>Chapter 3.1 --- Some Experimental Results --- p.13<br>Chapter 3.2 --- Discussion --- p.15<br>Chapter 4 --- Nearest Neighbor Search in VP-trees --- p.17<br>Chapter 4.1 --- The sigma-factor Algorithm --- p.18<br>Chapter 4.2 --- The Constant-α Algorithm --- p.22<br>Chapter 4.3 --- The Single-Pass Algorithm --- p.24<br>Chapter 4.4 --- Discussion --- p.25<br>Chapter 4.5 --- Performance Evaluation --- p.26<br>Chapter 4.5.1 --- Experimental Setup --- p.27<br>Chapter 4.5.2 --- Results --- p.28<br>Chapter 5 --- Update Operations on VP-trees --- p.41<br>Chapter 5.1 --- Insert --- p.41<br>Chapter 5.2 --- Delete --- p.48<br>Chapter 5.3 --- Performance Evaluation --- p.51<br>Chapter 6 --- Minimizing Distance Computations --- p.57<br>Chapter 6.1 --- A Single Vantage Point per Level --- p.58<br>Chapter 6.2 --- Reuse of Vantage Points --- p.59<br>Chapter 6.3 --- Performance Evaluation --- p.60<br>Chapter 7 --- Conclusions and Future Work --- p.63<br>Chapter 7.1 --- Future Work --- p.65<br>Bibliography --- p.67

“A picture is worth a thousand words”. If this proverb were taken literally we all know that every person interprets images or photos differently in terms of its content. This is due to the semantics contained in these images. Content-based image retrieval has become a vast area of research in order to successfully describe and retrieve images according to the content. In military applications, intelligence images such as those obtained by the defence intelligence group are taken (mostly on film), developed and then manually annotated thereafter. These photos are then stored in a filing system according to certain attributes such as the location, content etc. To retrieve these images at a later stage might take days or even weeks to locate. Thus, the need for a digital annotation system has arisen. The images of the military contain various military vehicles and buildings that need to be detected, described and stored in a database. For our research we want to look at the effects that the rotation and elevation angle of an object in an image has on the retrieval performance. We chose model cars in order to be able to control the environment the photos were taken in such as the background, lighting, distance between the objects, and the camera etc. There are also a wide variety of shapes and colours of these models to obtain and work with. We look at the MPEG-7 descriptor schemes that are recommended by the MPEG group for video and image retrieval as well as implement three of them. For the military it could be required that when the defence intelligence group is in the field, that the images be directly transmitted via satellite to the headquarters. We have therefore included the JPEG2000 standard which gives a compression performance increase of 20% over the original JPEG standard. It is also capable to transmit images wirelessly as well as securely. Including the MPEG-7 descriptors that we have implemented, we have also implemented the fuzzy histogram and colour correlogram descriptors. For our experimentation we implemented a series of experiments in order to determine the effects that rotation and elevation has on our model vehicle images. Observations are made when each vehicle is considered separately and when the vehicles are described and combined into a single database. After the experiments are done we look at the descriptors and determine which adjustments could be made in order to improve the retrieval performance thereof.<br>Dr. W.A. Clarke

碩士<br>國立成功大學<br>電腦與通信工程研究所<br>93<br>The concept of XML Information Object has been proposed by our research team. For management and reusing purpose, the Internet information is modelled as Information Object that can be manipulated and exchanged as a unit. We use an XML file as a unit to encapsulate text data and binary contents as an XML Object to realize the concept of Information Object. To realize the idea we have developed a storage management system called XML Document Storage (XDS). In addition, we have implemented the Information Sharing Workspace (ISW) as a workspace on which users can easily construct XML Objects and share XML Objects stored in XDS. 　　In this thesis, we will model the total system, both the XDS and the ISW to give a more clear view for exploring advanced topic or issues to be addressed in the future. In particular, we will pay much effort on the improving of binary contents attachment in an XML object. In the previous version of XDS, the binary content is BASE64-encoded and embedded in an element of an XML object for transmission on the wire. This way will incur a problem of XML object size limitation due to the implementation constraints of XML and language tools. Another problem is on the performance in manipulating binary contents. To cope with these problems, we define several kinds of attachment objects to represent the binary contents and linked to an XML object for transmission. With the new approach the size limitation and the efficiency on manipulating binary contents are improved.

Topic: The Efficiency of Designing and Applying the Multimedia Study Materials in the Chemistry Instruction at Grammar schools (Transition Elements) Abstract Numerous researches prove, that the computer-supported learning content presentations are frequently applied within the process of instruction but the available results are general, global without focusing on respondents' age structure, detecting their interest in working with presentation programmes or correlation to teachers' computer literacy, i.e. using and designing their own computer-supported presentations of the learning content. These were the main reasons why the dissertation thesis focuses on the frequency of designing and using this type of presentations and multimedia objects according to the computer literacy level and the length of respondents' teaching practice in chemistry at grammar schools in the Czech Republic, mainly in the Moravian-Silesian region. The explorative methods were applied in the pedagogical research, i.e. the questionnaire method (traditional questionnaire and the questionnaire with assessment scales) and the Q-methodology. The research sample consists of 203 chemistry teachers in the traditional questionnaire and 99 ones in the questionnaire with assessment scales from all regions of the Czech Republic; the random...

Throughout life, we continuously accumulate data, information and knowledge. The ability to recall much of this accumulated knowledge commonly deteriorates with time, though some forms part of what is referred to as tacit knowledge. In the context of education, students access and interact with a teacher’s knowledge in order to create their own, and may have their own data, information and knowledge that could be added to teacher’s knowledge for everyone’s benefit. The realization that students can contribute to enhancing personal knowledge is an important cornerstone in developing a mentor (teacher, tutor and facilitator) focused knowledge system. The research presented in this thesis discusses an integrated framework that manages an individual’s personal data, information and knowledge and enables it to be enhanced by others, in the context of a blended teaching and learning environment. Existing related models, structures, systems and current practices are discussed. The core outcomes of this thesis include: • the virtualMe framework that can be utilized when developing Web based teaching and learning systems; • the sniplet content model that can be used as the basis for sharing information and knowledge; • an annotation framework used to manage knowledge acquisition; and • a multimedia object (MMO) model that: o allows for related media artefacts to be intuitively grouped in a logical collection; o includes a meta-data schema that encompasses other metadata structures, and manages context and referencing; and o includes a model allowing component parts to be reaggregated if they are separated. The virtualMe framework provides the ability to retain context while transferring the content from one person to another and from one place to another. The framework retains the content’s original context and then allows the receiver to customise the content and metadata so that the content becomes that person’s knowledge. A mechanism has been created for such contextual transfer of content (context retained by the metadata).