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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

MPEG client software for set-top boxes of VoD systems

Zeng, Xianhong 01 April 2000 (has links)
No description available.
42

The effects of evaluation and rotation on descriptors and similarity measures for a single class of image objects

06 June 2008 (has links)
“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. / Dr. W.A. Clarke
43

Non-expansive symmetrically extended wavelet transform for arbitrarily shaped video object plane.

January 1998 (has links)
by Lai Chun Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 68-70). / Abstract also in Chinese. / ACKNOWLEDGMENTS --- p.IV / ABSTRACT --- p.v / Chapter Chapter 1 --- Traditional Image and Video Coding --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Fundamental Principle of Compression --- p.1 / Chapter 1.3 --- Entropy - Value of Information --- p.2 / Chapter 1.4 --- Performance Measure --- p.3 / Chapter 1.5 --- Image Coding Overview --- p.4 / Chapter 1.5.1 --- Digital Image Formation --- p.4 / Chapter 1.5.2 --- Needs of Image Compression --- p.4 / Chapter 1.5.3 --- Classification of Image Compression --- p.5 / Chapter 1.5.4 --- Transform Coding --- p.6 / Chapter 1.6 --- Video Coding Overview --- p.8 / Chapter Chapter 2 --- Discrete Wavelets Transform (DWT) and Subband Coding --- p.11 / Chapter 2.1 --- Subband Coding --- p.11 / Chapter 2.1.1 --- Introduction --- p.11 / Chapter 2.1.2 --- Quadrature Mirror Filters (QMFs) --- p.12 / Chapter 2.1.3 --- Subband Coding for Image --- p.13 / Chapter 2.2 --- Discrete Wavelets Transformation (DWT) --- p.15 / Chapter 2.2.1 --- Introduction --- p.15 / Chapter 2.2.2 --- Wavelet Theory --- p.15 / Chapter 2.2.3 --- Comparison Between Fourier Transform and Wavelet Transform --- p.16 / Chapter Chapter 3 --- Non-expansive Symmetric Extension --- p.19 / Chapter 3.1 --- Introduction --- p.19 / Chapter 3.2 --- Types of extension scheme --- p.19 / Chapter 3.3 --- Non-expansive Symmetric Extension and Symmetric Sub-sampling --- p.21 / Chapter Chapter 4 --- Content-based Video Coding in MPEG-4 Purposed Standard --- p.24 / Chapter 4.1 --- Introduction --- p.24 / Chapter 4.2 --- Motivation of the new MPEG-4 standard --- p.25 / Chapter 4.2.1 --- Changes in the production of audio-visual material --- p.25 / Chapter 4.2.2 --- Changes in the consumption of multimedia information --- p.25 / Chapter 4.2.3 --- Reuse of audio-visual material --- p.26 / Chapter 4.2.4 --- Changes in mode of implementation --- p.26 / Chapter 4.3 --- Objective of MPEG-4 standard --- p.27 / Chapter 4.4 --- Technical Description of MPEG-4 --- p.28 / Chapter 4.4.1 --- Overview of MPEG-4 coding system --- p.28 / Chapter 4.4.2 --- Shape Coding --- p.29 / Chapter 4.4.3 --- Shape Adaptive Texture Coding --- p.33 / Chapter 4.4.4 --- Motion Estimation and Compensation (ME/MC) --- p.35 / Chapter Chapter 5 --- Shape Adaptive Wavelet Transformation Coding Scheme (SA WT) --- p.36 / Chapter 5.1 --- Shape Adaptive Wavelet Transformation --- p.36 / Chapter 5.1.1 --- Introduction --- p.36 / Chapter 5.1.2 --- Description of Transformation Scheme --- p.37 / Chapter 5.2 --- Quantization --- p.40 / Chapter 5.3 --- Entropy Coding --- p.42 / Chapter 5.3.1 --- Introduction --- p.42 / Chapter 5.3.2 --- Stack Run Algorithm --- p.42 / Chapter 5.3.3 --- ZeroTree Entropy (ZTE) Coding Algorithm --- p.45 / Chapter 5.4 --- Binary Shape Coding --- p.49 / Chapter Chapter 6 --- Simulation --- p.51 / Chapter 6.1 --- Introduction --- p.51 / Chapter 6.2 --- SSAWT-Stack Run --- p.52 / Chapter 6.3 --- SSAWT-ZTR --- p.53 / Chapter 6.4 --- Simulation Results --- p.55 / Chapter 6.4.1 --- SSAWT - STACK --- p.55 / Chapter 6.4.2 --- SSAWT ´ؤ ZTE --- p.56 / Chapter 6.4.3 --- Comparison Result - Cjpeg and Wave03. --- p.57 / Chapter 6.5 --- Shape Coding Result --- p.61 / Chapter 6.6 --- Analysis --- p.63 / Chapter Chapter 7 --- Conclusion --- p.64 / Appendix A: Image Segmentation --- p.65 / Reference --- p.68
44

Media Scaling for Power Optimization on Wireless Video Sensors

Lu, Rui 23 August 2007 (has links)
"Video-based sensor networks can be used to improve environment surveillance, health care and emergency response. Many sensor network scenarios require multiple high quality video streams that share limited wireless bandwidth. At the same time, the lifetime of wireless video sensors are constrained by the capacity of their batteries. Media scaling may extend battery life by reducing the video data rate while still maintaining visual quality, but comes at the expense of additional compression time. This thesis studies the effects of media scaling on video sensor energy consumption by: measuring the energy consumption on the different components of the video sensor; building a energy consumption model with several adjustable parameters to analyze the performance of a video sensor; exploring the trade-offs between the video quality and the energy consumption for a video sensor; and, finally, building a working video sensor to validate the accuracy of the model. The results show that the model is an accurate representation of the power usage of an actual video sensor. In addition, media scaling is often an effective way to reduce energy consumption in a video sensor."
45

Object-based scalable wavelet image and video coding. / CUHK electronic theses & dissertations collection

January 2008 (has links)
The first part of this thesis studies advanced wavelet transform techniques for scalable still image object coding. In order to adapt to the content of a given signal and obtain more flexible adaptive representation, two advanced wavelet transform techniques, wavelet packet transform and directional wavelet transform, are developed for object-based image coding. Extensive experiments demonstrate that the new wavelet image coding systems perform comparable to or better than state-of-the-art in image compression while possessing some attractive features such as object-based coding functionality and high coding scalability. / The objective of this thesis is to develop an object-based coding framework built upon a family of wavelet coding techniques for a variety of arbitrarily shaped visual object scalable coding applications. Two kinds of arbitrarily shaped visual object scalable coding techniques are investigated in this thesis. One is object-based scalable wavelet still image coding; another is object-based scalable wavelet video coding. / The second part of this thesis investigates various components of object-based scalable wavelet video coding. A generalized 3-D object-based directional threading, which unifies the concepts of temporal motion threading and spatial directional threading, is seamlessly incorporated into 3-D shape-adaptive directional wavelet transform to exploit the spatio-temporal correlation inside the 3-D video object. To improve the computational efficiency of multi-resolution motion estimation (MRME) in shift-invariant wavelet domain, two fast MRME algorithms are proposed for wavelet-based scalable video coding. As demonstrated in the experiments, the proposed 3-D object-based wavelet video coding techniques consistently outperform MPEG-4 and other wavelet-based schemes for coding arbitrarily shaped video object, while providing full spatio-temporal-quality scalability with non-redundant 3-D subband decomposition. / Liu, Yu. / Adviser: King Ngi Ngan. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3693. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 166-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
46

Single camera based vision systems for ground and; aerial robots

Shah, Syed Irtiza Ali 11 August 2010 (has links)
Efficient and effective vision systems are proposed in this work for object detection for ground&aerial robots venturing into unknown environments with minimum vision aids, i.e. a single camera. The first problem attempted is that of object search and identification in a situation similar to a disaster site. Based on image analysis, typical pixel-based characteristics of a visual marker have been established to search for, using a block based search algorithm, along with a noise and interference filter. The proposed algorithm has been successfully utilized for the International Aerial Robotics competition 2009. The second problem deals with object detection for collision avoidance in 3D environments. It has been shown that a 3D model of the scene can be generated from 2D image information from a single camera flying through a very small arc of lateral flight around the object, without the need of capturing images from all sides. The forward flight simulations show that the depth extracted from forward motion is usable for large part of the image. After analyzing various constraints associated with this and other existing approaches, Motion Estimation has been proposed. Implementation of motion estimation on videos from onboard cameras resulted in various undesirable and noisy vectors. An in depth analysis of such vectors is presented and solutions are proposed and implemented, demonstrating desirable motion estimation for collision avoidance task.
47

Compressed-domain processing of MPEG audio signals

Lanciani, Christopher A. 06 1900 (has links)
No description available.
48

Spatio-temporal segmentation in the compressed domain

Jamrozik, Michele Lynn 12 1900 (has links)
No description available.
49

Transcoding transport stream mpeg2

Shilarnav, Shashi R. January 2007 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 5, 2007) Includes bibliographical references.
50

Extending an MPEG-21 viewer to manage access rights

Lönneborg, Rickard. January 2004 (has links)
Thesis (M.Sc.(Hons.))--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 61-63.

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