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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.
31

Topics on video postprocessing /

Chong, Tak Song. January 2005 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 103-106). Also available in electronic version.
32

Motion estimation and compensation for H.264 video coding /

Wong, Hoi Ming. January 2006 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 72-75). Also available in electronic version.
33

A new paradigm for multiple description video coding /

Liang, Zhiqin. January 2007 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 86-90). Also available in electronic version.
34

Adding lossless compression to MPEGs

Jiang, Jianmin, Xiao, G. January 2006 (has links)
Yes / In this correspondence, we propose to add a lossless compression functionality into existing MPEGs by developing a new context tree to drive arithmetic coding for lossless video compression. In comparison with the existing work on context tree design, the proposed algorithm features in 1) prefix sequence matching to locate the statistics model at the internal node nearest to the stopping point, where successful match of context sequence is broken; 2) traversing the context tree along a fixed order of context structure with a maximum number of four motion compensated errors; and 3) context thresholding to quantize the higher end of error values into a single statistics cluster. As a result,the proposed algorithm is able to achieve competitive processing speed, low computational complexity and high compression performances, which bridges the gap between universal statistics modeling and practical compression techniques. Extensive experiments show that the proposed algorithm outperforms JPEG-LS by up to 24% and CALIC by up to 22%, yet the processing time ranges from less than 2 seconds per frame to 6 seconds per frame on a typical PC computing platform.
35

Digital Video Telemetry System

Thom, Gary A., Snyder, Edwin 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The ability to acquire real-time video from flight test platforms is becoming an important requirement in many test programs. Video is often required to give the flight test engineers a view of critical events during a test such as instrumentation performance or weapons separation. Digital video systems are required because they allow encryption of the video information during transmission. This paper describes a Digital Video Telemetry System that uses improved video compression techniques which typically offer at least a 10:1 improvement in image quality over currently used techniques. This improvement is the result of inter-frame coding and motion compensation which other systems do not use. Better quality video at the same bit rate, or the same quality video at a lower bit rate is achieved. The Digital Video Telemetry System also provides for multiplexing the video information with other telemetered data prior to encryption.
36

Wavelet Based Video Compression for A Low-Rate Data Link

Landry, Michael W., Lee, Jeffrey C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Conventional video image transmission requires large data bandwidths, whether the signals are transmitted in analog or digital form. Many applications are limited to bandwidths that will not support image transmission unless high compression ratios are employed. Video compression techniques based on wavelet functions provide high data compression while preserving image quality, but are computationally demanding. Recently available high-integration devices that utilize wavelet basis functions for video compression have made possible low-cost high-performance video compression systems. Image data is more useful when provided with other data such as position information, telemetry, or other user data. This paper describes the technology, features, and limitations of a versatile low data rate system incorporating compressed video data.
37

IMPLEMENTATION OF REAL-TIME AIRBORNE VIDEO TELEMETRY SYSTEM

Nam, Ju-Hun, Choi, Byeong-Doo, Ko, Sung-Jea, Kim, Bok-Ki, Lee, Woon-Moon, Lee, Nam-Sik, Yu, Jea-Taeg 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / In this paper, we present an efficient real-time implementation technique for Motion-JPEG2000 video compression and its reconstruction used for a real-time Airborne Video Telemetry System. we utilize Motion JPEG2000 and 256-channel PCM Encoder was used for source coding in the developed system. Especially, in multiplexing and demultiplexing PCM encoded data, we use the continuous bit-stream format of the PCM encoded data so that any de-commutator can use it directly, after demultiplexing. Experimental results show that our proposed technique is a practical and an efficient DSP solution.
38

Adaptive techniques for scalable video compression

Mehrseresht, Nagita, Electrical Engineering & communication, UNSW January 2005 (has links)
In this work we investigate adaptive techniques which can be used to improve the performance of highly scalable video compression schemes under resolution scaling. We propose novel content adaptive methods for motion compensated 3D discrete wavelet transformation (MC 3D-DWT) of video. The proposed methods overcome problems of ghosting and non-aligned aliasing artifacts, which can arise in regions of motion model failure, when the video is reconstructed at reduced temporal or spatial resolutions. We also study schemes which facilitate simultaneous scaling of compressed video bitstreams based on both constant bit-rate and constant distortion criteria, using simple and generic scaling operations. In regions where the motion model fails, the motion compensated temporal discrete wavelet transform (MC TDWT) causes ghosting artifacts under frame-rate scaling, due to temporal lowpass filtering along invalid motion trajectories. To avoid ghosting artifacts, we adaptively select between different lowpass filters, based on a local estimate of the motion modelling accuracy. Experimental results indicate that the proposed adaptive transform substantially removes ghosting artifacts while also preserving the high compression efficiency of the original MC TDWT. We also study the impact of various MC 3D-DWT structures on spatial scalability. Investigating the interaction between spatial aliasing, scalability and energy compaction shows that the t+2D structure essentially has higher compression efficiency. However, where the motion model fails, structures of this form cause non-aligned aliasing artifacts under spatial scaling. We propose novel adaptive schemes to continuously adapt the structure of MC 3D-DWT based on information available within the compressed bitstream. Experimental results indicate that the proposed adaptive structure preserves the high compression efficiency of the t+2D structure while also avoiding the appearance of non-aligned aliasing artifacts under spatial scaling. To provide simultaneous rate and distortion scaling, we study ???layered substream structure. Scaling based on distortion generates variable bit-rate traffic which satisfies the desired average bit-rate and is consistent with the requirements of leaky-bucket traffic models. We propose a novel method which also satisfies constraints on instantaneous bit-rate. This method overcomes the weakness of previous methods with small leaky-bucket buffer sizes. Simulation results indicate promising performance with both MC 3D-DWT interframe and JPEG2000 intraframe compression.
39

Rate control based on human visual perception characteristics and its application in encoding time-lapse video /

Nguyen, Anthony Giang. January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 111-116).
40

Video coding for transport over wireless channels /

Aramvith, Supavadee. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 113-117).

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