Spelling suggestions: "subject:"video compression techniques"" "subject:"ideo compression techniques""
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Knowledge based image sequence compressionZhang, Kui January 1998 (has links)
In this thesis, most commonly encountered video compression techniques and international coding standards are studied. The study leads to the idea of a reconfigurable codec which can adapt itself to the specific requirements of diverse applications so as to achieve improved performance. Firstly, we propose a multiple layer affine motion compensated codec which acts as a basic building block of the reconfigurable multiple tool video codec. A detailed investigation of the properties of the proposed codec is carried out. The experimental results reveal that the gain in coding efficiency from improved motion prediction and segmentation is proportional to the spatial complexity of the sequence being encoded. Secondly, a framework for the reconfigurable multiple tool video codec is developed and its key parts are discussed in detail. Two important concepts virtual codec and virtual tool are introduced. A prototype of the proposed reconfigurable multiple tool video codec is implemented. The codec structure and the constituent tools of the codec included in the prototype are extensively tested and evaluated to prove the concept. The results confirm that different applications require different codec configurations to achieve optimum performance. Thirdly, a knowledge based tool selection system for the reconfigurable codec is proposed and developed. Human knowledge as well as sequence properties are taken into account in the tool selection procedure. It is shown that the proposed tool selection mechanism gives promising results. Finally, concluding remarks are offered and future research directions are suggested.
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Estimation of LRD present in H.264 video traces using wavelet analysis and proving the paramount of H.264 using OPF technique in wi-fi environmentJayaseelan, John January 2012 (has links)
While there has always been a tremendous demand for streaming video over Wireless networks, the nature of the application still presents some challenging issues. These applications that transmit coded video sequence data over best-effort networks like the Internet, the application must cope with the changing network behaviour; especially, the source encoder rate should be controlled based on feedback from a channel estimator that explores the network intermittently. The arrival of powerful video compression techniques such as H.264, which advance in networking and telecommunications, opened up a whole new frontier for multimedia communications. The aim of this research is to transmit the H.264 coded video frames in the wireless network with maximum reliability and in a very efficient manner. When the H.264 encoded video sequences are to be transmitted through wireless network, it faces major difficulties in reaching the destination. The characteristics of H.264 video coded sequences are studied fully and their capability of transmitting in wireless networks are examined and a new approach called Optimal Packet Fragmentation (OPF) is framed and the H.264 coded sequences are tested in the wireless simulated environment. This research has three major studies involved in it. First part of the research has the study about Long Range Dependence (LRD) and the ways by which the self-similarity can be estimated. For estimating the LRD a few studies are carried out and Wavelet-based estimator is selected for the research because Wavelets incarcerate both time and frequency features in the data and regularly provides a more affluent picture than the classical Fourier analysis. The Wavelet used to estimate the self-similarity by using the variable called Hurst Parameter. Hurst Parameter tells the researcher about how a data can behave inside the transmitted network. This Hurst Parameter should be calculated for a more reliable transmission in the wireless network. The second part of the research deals with MPEG-4 and H.264 encoder. The study is carried out to prove which encoder is superior to the other. We need to know which encoder can provide excellent Quality of Service (QoS) and reliability. This study proves with the help of Hurst parameter that H.264 is superior to MPEG-4. The third part of the study is the vital part in this research; it deals with the H.264 video coded frames that are segmented into optimal packet size in the MAC Layer for an efficient and more reliable transfer in the wireless network. Finally the H.264 encoded video frames incorporated with the Optimal Packet Fragmentation are tested in the NS-2 wireless simulated network. The research proves the superiority of H.264 video encoder and OPF's master class.
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Estimation of LRD present in H.264 video traces using wavelet analysis and proving the paramount of H.264 using OPF technique in wi-fi environment.Jayaseelan, John January 2012 (has links)
While there has always been a tremendous demand for streaming video over
Wireless networks, the nature of the application still presents some challenging
issues. These applications that transmit coded video sequence data over best-effort
networks like the Internet, the application must cope with the changing network
behaviour; especially, the source encoder rate should be controlled based on
feedback from a channel estimator that explores the network intermittently. The
arrival of powerful video compression techniques such as H.264, which advance in
networking and telecommunications, opened up a whole new frontier for multimedia
communications. The aim of this research is to transmit the H.264 coded video
frames in the wireless network with maximum reliability and in a very efficient
manner. When the H.264 encoded video sequences are to be transmitted through
wireless network, it faces major difficulties in reaching the destination. The
characteristics of H.264 video coded sequences are studied fully and their capability
of transmitting in wireless networks are examined and a new approach called
Optimal Packet Fragmentation (OPF) is framed and the H.264 coded sequences are
tested in the wireless simulated environment. This research has three major studies
involved in it. First part of the research has the study about Long Range Dependence
(LRD) and the ways by which the self-similarity can be estimated. For estimating the
LRD a few studies are carried out and Wavelet-based estimator is selected for the
research because Wavelets incarcerate both time and frequency features in the data
and regularly provides a more affluent picture than the classical Fourier analysis.
The Wavelet used to estimate the self-similarity by using the variable called Hurst
Parameter. Hurst Parameter tells the researcher about how a data can behave inside the transmitted network. This Hurst Parameter should be calculated for a more
reliable transmission in the wireless network. The second part of the research deals
with MPEG-4 and H.264 encoder. The study is carried out to prove which encoder is
superior to the other. We need to know which encoder can provide excellent Quality
of Service (QoS) and reliability. This study proves with the help of Hurst parameter
that H.264 is superior to MPEG-4. The third part of the study is the vital part in this
research; it deals with the H.264 video coded frames that are segmented into optimal
packet size in the MAC Layer for an efficient and more reliable transfer in the
wireless network. Finally the H.264 encoded video frames incorporated with the
Optimal Packet Fragmentation are tested in the NS-2 wireless simulated network.
The research proves the superiority of H.264 video encoder and OPF¿s master class.
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