Video Signal
Mostrando 25-36 de 68 artigos, teses e dissertações.
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25. Sistema de codificação de video baseado em transformadas tridimensionais, rapidas e progressivas / Video coding system based on three dimensional, fast and progressive transforms
The research on video coding systems has always been looking for techniques that can reach the highest possible compression rate. This compression rate increase is generally achieved by means of increased coding complexity, which is supported by the continuous increase verified in computational power. However, in some video coding and transmission situations
Publicado em: 2007
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26. ALGORITMO RÁPIDO DE ESTIMAÇÃO ADAPTATIVO AO MOVIMENTO APLICADO AO CODIFICADOR PADRÃO H.264/AVC / FAST MOTION ADAPTIVE ESTIMATION ALGORITHM APPLIED TO THE H.261/AVC STANDARD CODER
As técnicas de estimação de movimento utilizadas nos padrões de compressão de vídeo proporcionam a utilização mais eficiente dos recursos de transmissão e armazenamento, através da redução do número de bits necessários para representar um sinal de vídeo e da conservação da qualidade do conteúdo que está sendo processado. O objetivo dessa d
Publicado em: 2007
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27. Study of the audio coding algorithm of the MPEG-4 AAC standard and comparison among implementations of modules of the algorithm
Audio coding is used to compress digital audio signals, thereby reducing the amount of bits needed to transmit or to store an audio signal. This is useful when network bandwidth or storage capacity is very limited. Audio compression algorithms are based on an encoding and decoding process. In the encoding step, the uncompressed audio signal is transformed in
Publicado em: 2007
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28. CLASSIFICAÇÃO E SEGMENTAÇÃO DE ÁUDIO A PARTIR DE FATORES DE ESCALA MPEG / CLASSIFICATION AND SEGMENTATION OF MPEG AUDIO BASED ON SCALE FACTORS
With the growth of production and storing of digital media, audio segmentation and classification are becoming increasingly important. This work is based on characteristics of the MPEG standard, considered to be the standard for digital media storage and retrieval, to propose efficient algorithms to perform these tasks. While there are many studies based on
Publicado em: 2007
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29. AvaliaÃÃo da qualidade de vÃdeo trafegando sobre redes IP / Evaluation of the quality of video passing through on nets IP
O uso das redes de computadores, em especial redes IP, jà à realidade para distribuiÃÃo e troca de conteÃdo multimÃdia. Oferecem, dada sua capilaridade, uma opÃÃo econÃmica inclusive para a contribuiÃÃo e distribuiÃÃo de vÃdeo de emissoras e redes de televisÃo. No entanto, o material de vÃdeo e Ãudio apresenta normalmente caracterÃsticas de
Publicado em: 2007
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30. Amplificadores Ãpticos, estudos de polarizaÃÃo e geraÃÃo de pulso usando processos paramÃtricos em fibras Ãpticas
The recent telecommunication development can be, to a large extent, attributed to the capacity of transmitting information (video, sound and data) at high transmission rates (Tbits/s) through the optical fiber. The constant advances in the technological development of active and passive devices based on optical fibers have enabled a steady increase in commun
Publicado em: 2007
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31. Computerized invasive measurement of time-dependent intraocular pressure
Several methods have been described to measure intraocular pressure (IOP) in clinical and research situations. However, the measurement of time varying IOP with high accuracy, mainly in situations that alter corneal properties, has not been reported until now. The present report describes a computerized system capable of recording the transitory variability
Brazilian Journal of Medical and Biological Research. Publicado em: 2006-09
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32. Distributed coding turbo codes and second generation wavelets / Codificação distribuida de video digital utilizando codigos turbo e Waveletes de segunda geração
Distributed video coding is a new paradigm for video compression in opposition over the existing video coding standards like MPEG-x and H.26x families. These codecs make use of motion estimation algorithms, the main part of the compression process of the video signal. Hence, the compression process demands a high computational cost and high performance of th
Publicado em: 2006
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33. Metodo de sincronização de cameras de video utilizando a banda de audio
This work proposes and evaluates a novel method for synchronisation of video cameras using the audio band. The method consists in generating and transmitting an audio signal through radio frequency for receivers connected to the microphone input of the cameras and inserting the signal in the audio band. In a software environment, the phase differences among
Publicado em: 2005
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34. Algoritmo de casamento de padrões aplicado na estimação de movimento em compressão de video
With the application of motion estimation and compensation techniques in video sequences, we can reduce the number of bits needed to encode the video sequence and to increase the quality of the reconstructed video signal. On the other hand, the high computational cost of the process demands high performance of the encoder. This thesis proposes a new motion e
Publicado em: 2003
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35. MATHEMATICAL AND EXPERIMENTAL APPROACHES IN SHAPE-ADAPTATIVE VIDEO CODING / ABORDAGENS MATEMÁTICAS E EXPERIMENTAIS EM CODIFICAÇÃO DE VÍDEO ADAPTATIVA À FORMA
This thesis investigates shape adaptative coding of arbitrarily shaped segments. The texture and contour coding efficiency is discussed and solutions to tackle the associated problems are proposed. The presented methods are evaluated using standard image sequences. A mathematical approach for shape-adaptative transforms using linear operators is developed, f
Publicado em: 2000
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36. Transmissão robusta de video em pacotes
The objective of this work is to study the quality of video signals transmitted over wideband networks subject to packet losses. Increased transmission robustness is achieved by "scalability" or layered segmentation of the video signal. We consider spectral separation and requantization methods of scalability, as well as different levels of packet losses and
Publicado em: 1998