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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.
61

Error-resilient techniques for packet video communications /

Chen, Wu-hsiang Jonas. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 117-124).
62

Video transmission over low bit-rate half-duplex wireless networks /

Cao, Zhenyu, January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 84-90). Also available in electronic format on the Internet.
63

Image data compression using multiple bases representation

Khanna, Rajiv 30 December 2008 (has links)
The compression of gray scale images is an interesting problem because of the large number of variations between data elements while maintaining a high degree of correlation. The goal of image data compression is to obtain the best possible image for a fixed information rate. In recent years, there has been a lot of research into the efficient coding of gray scale images. Vector quantization (Va) methods have been successfully applied to the efficient coding of images. These methods, however, are computationally intensive. Full search Multiple Bases Representation (MBR) is similar to Va in many respects. The Recursive Residual Projection (RRP) algorithm, a sub-optimal implementation of full search MBR, has been found to perform well. In this thesis, we apply MBR (using the RRP algorithm) to the compression of image data. We develop an image coding system that allows for a comparison of MBR with some well studied transform coding methods: the Discrete Cosine Transform (DeI) and the Fast Haar Transform (FHT) coding methods. We find that the DCf based coder performs at 1.5 bits/pixel with good image quality and that the FlIT based coder performs at 0.81 bits/pixel with some disconcerting characteristics. The RRP based coder outperforms the ncr based coder at 1.1 bits/pixel with very good image quality. We also tested a modified version of the RRP algorithm that used 3 orthogonal sets of basis vectors. We found that the modified RRP algorithm generally reduced the number of representation coefficients and improved image quality. We also found that the modified RRP algorithm performed worse than the RRP algorithm due to an increase in symbol entropy. / Master of Science
64

Adaptation of variable-bit-rate compressed video for transport over a constant-bit-rate communication channel in broadband networks.

January 1995 (has links)
by Chi-yin Tse. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 118-[121]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Video Compression and Transport --- p.2 / Chapter 1.2 --- VBR-CBR Adaptation of Video Traffic --- p.5 / Chapter 1.3 --- Research Contributions --- p.7 / Chapter 1.3.1 --- Spatial Smoothing: Video Aggregation --- p.8 / Chapter 1.3.2 --- Temporal Smoothing: A Control-Theoretic Study。 --- p.8 / Chapter 1.4 --- Organization of Thesis --- p.9 / Chapter 2 --- Preliminaries --- p.13 / Chapter 2.1 --- MPEG Compression Scheme --- p.13 / Chapter 2.2 --- Problems of Transmitting MPEG Video --- p.17 / Chapter 2.3 --- Two-layer Coding and Transport Strategy --- p.19 / Chapter 2.3.1 --- Framework of MPEG-based Layering --- p.19 / Chapter 2.3.2 --- Transmission of GS and ES --- p.20 / Chapter 2.3.3 --- Problems of Two-layer Video Transmission --- p.20 / Chapter 3 --- Video Aggregation --- p.24 / Chapter 3.1 --- Motivation and Basic Concept of Video Aggregation --- p.25 / Chapter 3.1.1 --- Description of Video Aggregation --- p.28 / Chapter 3.2 --- MPEG Video Aggregation System --- p.29 / Chapter 3.2.1 --- Shortcomings of the MPEG Video Bundle Scenario with Two-Layer Coding and Cell-Level Multiplexing --- p.29 / Chapter 3.2.2 --- MPEG Video Aggregation --- p.31 / Chapter 3.2.3 --- MPEG Video Aggregation System Architecture --- p.33 / Chapter 3.3 --- Variations of MPEG Video Aggregation System --- p.35 / Chapter 3.4 --- Experimental Results --- p.38 / Chapter 3.4.1 --- Comparison of Video Aggregation and Cell-level Multi- plexing --- p.40 / Chapter 3.4.2 --- Varying Amount of the Allocated Bandwidth --- p.48 / Chapter 3.4.3 --- Varying Number of Sequences --- p.50 / Chapter 3.5 --- Conclusion --- p.53 / Chapter 3.6 --- Appendix: Alternative Implementation of MPEG Video Aggre- gation --- p.53 / Chapter 3.6.1 --- Profile Approach --- p.54 / Chapter 3.6.2 --- Bit-Plane Approach --- p.54 / Chapter 4 --- A Control-Theoretic Study of Video Traffic Adaptation --- p.58 / Chapter 4.1 --- Review of Previous Adaptation Schemes --- p.60 / Chapter 4.1.1 --- A Generic Model for Adaptation Scheme --- p.60 / Chapter 4.1.2 --- Objectives of Adaptation Controller --- p.61 / Chapter 4.2 --- Motivation for Control-Theoretic Study --- p.64 / Chapter 4.3 --- Linear Feedback Controller Model --- p.64 / Chapter 4.3.1 --- Encoder Model --- p.65 / Chapter 4.3.2 --- Adaptation Controller Model --- p.69 / Chapter 4.4 --- Analysis --- p.72 / Chapter 4.4.1 --- Stability --- p.73 / Chapter 4.4.2 --- Robustness against Coding-mode Switching --- p.83 / Chapter 4.4.3 --- Unit-Step Responses and Unit-Sample Responses --- p.84 / Chapter 4.5 --- Implementation --- p.91 / Chapter 4.6 --- Experimental Results --- p.95 / Chapter 4.6.1 --- Overall Performance of the Adaptation Scheme --- p.97 / Chapter 4.6.2 --- Weak-Control verus Strong-Control --- p.99 / Chapter 4.6.3 --- Varying Amount of Reserved Bandwidth --- p.101 / Chapter 4.7 --- Conclusion --- p.103 / Chapter 4.8 --- Appendix I: Further Research --- p.103 / Chapter 4.9 --- Appendix II: Review of Previous Adaptation Schemes --- p.106 / Chapter 4.9.1 --- Watanabe. et. al.'s Scheme --- p.106 / Chapter 4.9.2 --- MPEG's Scheme --- p.107 / Chapter 4.9.3 --- Lee et.al.'s Modification --- p.109 / Chapter 4.9.4 --- Chen's Adaptation Scheme --- p.110 / Chapter 5 --- Conclusion --- p.116 / Bibliography --- p.118
65

Image coding with a lapped orthogonal transform.

January 1993 (has links)
by Patrick Chi-man Fung. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 57-58). / LIST OF FIGURES / LIST OF IMAGES / LIST OF TABLES / NOTATIONS / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 2 --- THEORY --- p.3 / Chapter 2.1 --- Matrix Representation of LOT --- p.3 / Chapter 2.2 --- Feasibility of LOT --- p.5 / Chapter 2.3 --- Properties of Good Feasible LOT --- p.6 / Chapter 2.4 --- An Optimal LOT --- p.7 / Chapter 2.5 --- Approximation of an Optimal LOT --- p.10 / Chapter 2.6 --- Representation of an Approximately Optimal LOT --- p.13 / Chapter 3 --- IMPLEMENTATION --- p.17 / Chapter 3.1 --- Mathematical Background --- p.17 / Chapter 3.2 --- Analysis of LOT Flowgraph --- p.17 / Chapter 3.2.1 --- The Fundamental LOT Building Block --- p.17 / Chapter 3.2.2 --- +1/-1 Butterflies --- p.19 / Chapter 3.3 --- Conclusion --- p.25 / Chapter 4 --- RESULTS --- p.27 / Chapter 4.1 --- Objective of Energy Packing --- p.27 / Chapter 4.2 --- Nature of Target Images --- p.27 / Chapter 4.3 --- Methodology of LOT Coefficient Selection --- p.28 / Chapter 4.4 --- dB RMS Error in Pixel Values --- p.29 / Chapter 4.5 --- Negative Pixel Values in Reverse LOT --- p.30 / Chapter 4.6 --- LOT Coefficient Energy Distribution --- p.30 / Chapter 4.7 --- Experimental Data --- p.32 / Chapter 5 --- DISCUSSION AND CONCLUSIONS --- p.46 / Chapter 5.1 --- RMS Error (dB) and LOT Coeffs. Drop Ratio --- p.46 / Chapter 5.1.1 --- Numeric Experimental Results --- p.46 / Chapter 5.1.2 --- Human Visual Response --- p.46 / Chapter 5.1.3 --- Conclusion --- p.49 / Chapter 5.2 --- Number of Negative Pixel Values in RLOT --- p.50 / Chapter 5.3 --- LOT Coefficient Energy Distribution --- p.51 / Chapter 5.4 --- Effect of Changing the Block Size --- p.54 / REFERENCES --- p.57 / APPENDIX / Tables of Experimental Data --- p.59
66

Reliable video transmission over internet.

January 2000 (has links)
by Sze Ho Pong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 50-[53]). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Related Work --- p.3 / Chapter 1.2 --- Contributions of the Thesis --- p.3 / Chapter 1.3 --- Organization of the Thesis --- p.4 / Chapter 2 --- Background --- p.5 / Chapter 2.1 --- Best-effort Internet - The Lossy Network --- p.5 / Chapter 2.2 --- Effects of Packet Loss on Streamed Video --- p.7 / Chapter 2.3 --- Loss Recovery Schemes in Video Streaming --- p.8 / Chapter 3 --- Comparison of Two Packet-Loss Detection Schemes --- p.10 / Chapter 3.1 --- Gap Detection (GD) --- p.12 / Chapter 3.2 --- Time-Out (TO) Detection --- p.14 / Chapter 3.3 --- Mathematical Comparison --- p.17 / Chapter 4 --- The Combined Loss-Detection Algorithm --- p.21 / Chapter 4.1 --- System Architecture --- p.22 / Chapter 4.2 --- Loss Detection and Recovery --- p.23 / Chapter 4.2.1 --- Detecting Data Packet Losses Transmitted for First Time --- p.24 / Chapter 4.2.2 --- Detecting Losses of Retransmitted Packet --- p.28 / Chapter 4.3 --- Buffering Techniques --- p.32 / Chapter 4.3.1 --- Determining Packet-Loss Rate in Presentation --- p.33 / Chapter 4.4 --- Mapping Packet-Loss Rate to Degradation of Video Quality --- p.38 / Chapter 5 --- Experimental Results and Analysis --- p.40 / Chapter 5.1 --- Experimental Setup --- p.40 / Chapter 5.2 --- Small Delay Jitter Environment --- p.42 / Chapter 5.3 --- Large Delay Jitter Environment --- p.44 / Chapter 5.3.1 --- Using Low Bit-Rate Stream --- p.44 / Chapter 5.3.2 --- Using High Bit-Rate Stream --- p.44 / Chapter 6 --- Conclusions and Future Work --- p.47 / Chapter 6.1 --- Conclusions --- p.47 / Chapter 6.2 --- Future Work --- p.49 / Bibliography --- p.50
67

TCP-friendly video transmission over the internet.

January 2001 (has links)
by Chan Ho Chow. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 65-67). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Background --- p.5 / Chapter 2.1. --- Packet Loss in the Internet --- p.5 / Chapter 2.2. --- Shared Internet --- p.7 / Chapter 2.3. --- Video Streaming --- p.10 / Chapter 2.4. --- Real-time video transmission criteria --- p.11 / Chapter 2.5. --- Existing Video Streaming Protocol --- p.13 / Chapter Chapter 3 --- Transmission Control Protocol (TCP) --- p.16 / Chapter Chapter 4 --- Variable-rate Streaming TCP (VarS-TCP) --- p.22 / Chapter 4.1. --- General Idea --- p.22 / Chapter 4.2. --- Assumptions --- p.25 / Chapter 4.3. --- VarS-TCP Algorithm --- p.26 / Chapter 4.3.1. --- Connection Initialization --- p.26 / Chapter 4.3.2. --- Normal Data Transfer --- p.27 / Chapter 4.4. --- Skipping packets in TCP --- p.32 / Chapter 4.4.1. --- Types of skipped packet --- p.32 / Chapter 4.4.2. --- Acknowledging skipped packets --- p.34 / Chapter 4.4.3. --- Maintaining Normal Data Flow --- p.35 / Chapter 4.4.4. --- Congestion Control --- p.37 / Chapter 4.4.5. --- Packets skipped by receiver --- p.41 / Chapter 4.5. --- Rebuffering --- p.44 / Chapter Chapter 5 --- Simulation Result --- p.45 / Chapter 5.1. --- Accumulating Data --- p.46 / Chapter 5.2. --- Delay Constraints --- p.48 / Chapter 5.3. --- Adapting network situation --- p.50 / Chapter 5.4. --- Sharing bandwidth with TCP --- p.52 / Chapter 5.5. --- Random Traffic --- p.58 / Chapter 5.6. --- Effect of packet skip threshold --- p.59 / Chapter 5.7. --- Effect of round-trip-time --- p.61 / Chapter Chapter 6 --- Conclusion and Future Works --- p.63 / Bibliography --- p.65
68

Resource allocation in digital mobile systems.

January 1998 (has links)
by Wan Wai Leung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 77-[80]). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Wireless Multimedia System --- p.1 / Chapter 1.2 --- Motivation of this thesis --- p.2 / Chapter 1.3 --- The theme of this thesis --- p.4 / Chapter 1.3.1 --- System Model and Assumptions --- p.4 / Chapter 1.3.2 --- Outline of the thesis --- p.5 / Chapter 2 --- Overview of TDMA/FDMA Digital Cellular Systems --- p.7 / Chapter 2.1 --- The Cellular Concept --- p.7 / Chapter 2.2 --- Channel Assignment Strategies --- p.9 / Chapter 2.2.1 --- Fixed Channel Assignment --- p.9 / Chapter 2.2.2 --- Dynamic Channel Assignment --- p.9 / Chapter 2.3 --- Multiple Access Techniques --- p.10 / Chapter 2.3.1 --- Introduction to Multiple Access --- p.10 / Chapter 2.3.2 --- Frequency Division Multiple Access - FDMA --- p.11 / Chapter 2.3.3 --- Time Division Multiple Access - TDMA --- p.12 / Chapter 2.4 --- A TDMA/FDMA System - GSM --- p.13 / Chapter 2.4.1 --- Global System for Mobile --- p.13 / Chapter 2.4.2 --- GSM radio subsystem --- p.13 / Chapter 3 --- Multi-rate Data in TDMA/FDMA Digital Cellular Systems --- p.17 / Chapter 3.1 --- Incorporation of Multimedia Data --- p.17 / Chapter 3.2 --- A Global Optimal Strategy --- p.19 / Chapter 3.2.1 --- Channel Rearrangement --- p.19 / Chapter 3.2.2 --- Analytical Performance Analysis of a Special Case --- p.21 / Chapter 3.2.3 --- Numerical Results --- p.24 / Chapter 3.2.4 --- Issues in Channel Rearrangement --- p.25 / Chapter 4 --- Multiple Slots Allocations --- p.26 / Chapter 4.1 --- Introduction --- p.26 / Chapter 4.2 --- No-Split Algorithm --- p.27 / Chapter 4.2.1 --- No-Split Algorithm --- p.27 / Chapter 4.2.2 --- Pros and Cons --- p.28 / Chapter 4.3 --- Best Fit Algorithm --- p.29 / Chapter 4.3.1 --- Best Fit Algorithm --- p.29 / Chapter 4.3.2 --- Optimization --- p.31 / Chapter 4.3.3 --- Pros and Cons --- p.32 / Chapter 4.4 --- Comparison of the two algorithms --- p.32 / Chapter 5 --- Buddy Algorithm --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- Buddy System in Memory Management --- p.38 / Chapter 5.3 --- Buddy Algorithm --- p.40 / Chapter 5.3.1 --- Adaptation in slot allocation --- p.40 / Chapter 5.3.2 --- Data structure --- p.40 / Chapter 5.3.3 --- Slot allocation --- p.40 / Chapter 5.3.4 --- Slot deallocation --- p.44 / Chapter 5.4 --- Inference Property --- p.45 / Chapter 5.4.1 --- Proof of the Inference Property --- p.47 / Chapter 5.5 --- Pros and Cons --- p.49 / Chapter 6 --- Performance Study --- p.51 / Chapter 6.1 --- Introduction --- p.51 / Chapter 6.2 --- Fixed Channel Assignment --- p.52 / Chapter 6.2.1 --- System Parameters --- p.52 / Chapter 6.2.2 --- Simulation Results --- p.53 / Chapter 6.3 --- Dynmaic Channel Assignment --- p.55 / Chapter 6.3.1 --- System Parameters --- p.55 / Chapter 6.3.2 --- Simulation Results --- p.56 / Chapter 7 --- A Case Study - H.263 Video Coding --- p.59 / Chapter 7.1 --- CCITT H.263 Image Compression --- p.59 / Chapter 7.2 --- On a GSM Network --- p.60 / Chapter 8 --- Conclusion --- p.63 / Chapter A --- A General Data + Voice System with Channel Rearrangement --- p.65 / Chapter A.1 --- System Model --- p.65 / Chapter A.2 --- Markovian Analysis --- p.66 / Chapter B --- NP-Completeness Proof of the Best Fit Algorithm --- p.69 / Chapter B.1 --- CONSTRAINT SUBSET-SUM Problem --- p.69 / Chapter B.2 --- BEST-FIT Problem --- p.72 / Chapter C --- Proof of Proposition 5.2 --- p.74 / Chapter C.1 --- Upper Bound on Demand Advancement --- p.74 / Chapter C.2 --- Proof of Proposition 5.2 --- p.75 / Bibliography --- p.77
69

An end-to-end adaptation algorithm for best effort video delivery over Internet.

January 1998 (has links)
by Walter Chi-Woon Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 64-[67]). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Limitation of Existing Research --- p.3 / Chapter 1.3 --- Contributions of This Thesis --- p.3 / Chapter 1.4 --- Organization of the Thesis --- p.4 / Chapter 2 --- Related Work --- p.5 / Chapter 2.1 --- Ongoing Efforts For The Support of Real Time Applications on the Internet - RTP --- p.5 / Chapter 2.2 --- Using the Algorithm on top of RTP --- p.7 / Chapter 3 --- An Adaptive Video Retrieval Algorithm --- p.9 / Chapter 3.1 --- Lossless Environment --- p.9 / Chapter 3.1.1 --- Adapting the Request Rate to the Available Bandwidth --- p.12 / Chapter 3.2 --- Lossy Environment --- p.17 / Chapter 3.2.1 --- Adapting Ar in Lossy Environment --- p.20 / Chapter 3.3 --- Adjusting the Window Size --- p.24 / Chapter 3.4 --- Measurement Issues --- p.27 / Chapter 3.5 --- Mapping between Data Rate and Frame Rate --- p.28 / Chapter 4 --- Rate Measurement --- p.30 / Chapter 4.1 --- Arrival Rate Estimation --- p.30 / Chapter 4.2 --- Loss Rate Estimation --- p.32 / Chapter 5 --- Frame Skipping and Stuffing --- p.37 / Chapter 5.1 --- MPEG-1 Video Stream Basics --- p.37 / Chapter 5.2 --- Frame Skipping --- p.38 / Chapter 5.3 --- Frame Stuffing In Lossy Environment --- p.40 / Chapter 6 --- Experiment Result and Analysis --- p.43 / Chapter 6.1 --- Experiment --- p.43 / Chapter 6.2 --- Analysis --- p.54 / Chapter 6.2.1 --- Interacting With Streams With No Rate Control --- p.56 / Chapter 6.2.2 --- Multiple Streams Running The Algorithm --- p.58 / Chapter 6.2.3 --- Calculation of p --- p.59 / Chapter 7 --- Conclusions --- p.61 / Bibliography --- p.64
70

A microprocessor implementation of an image enhancement/transmission system

Gallington, Raleigh Cedric January 1981 (has links)
Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 147-148. / by Raleigh Cedric Gallington. / Elec.E

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