نتایج جستجو برای: wolf coded quantization

تعداد نتایج: 61766  

2005
Jingyu Yang Qionghai Dai Wenli Xu Rong Ding

The demand of transcoding MPEG-2 to H.264 will be raised as the H.264 promises higher coding efficiency over previous video compression standards, while MEPG-2 has been widely adopted in many existing systems. This paper presents a rate control scheme for MPEG-2 to H.264 transcoder with the consideration of peak signal-to-noise ratio (PSNR) fluctuation control and re-quantized quality loss redu...

Journal: :J. Visual Communication and Image Representation 2007
Ulug Bayazit Ozgur Orcay Umut Konur Fikret S. Gürgen

In predictive 3-D mesh geometry coding, the position of each vertex is predicted from the previously coded neighboring vertices and the resultant prediction error vectors are coded. In this work, the prediction error vectors are represented in a local coordinate system in order to cluster them around a subset of a 2-D planar subspace and thereby increase block coding efficiency. Alphabet entrop...

Journal: :IEEE Trans. Circuits Syst. Video Techn. 1997
Jiann-Jone Chen Hsueh-Ming Hang

In the first part of this paper, we derive a source model describing the relationship between bits, distortion, and quantization step size for transform coders. Based on this source model, a variable frame rate coding algorithm is developed. The basic idea is to select a proper picture frame rate to ensure a minimum picture quality for every frame. Because our source model can predict approxima...

2003
Marcos MartIn-Fernández

In this paper we propose a novel lossless coding scheme for medical images that allows the final user to switch between a lossy and a lossless mode. This is done by means of a progressive reconstruction philosophy (which can be interrupted at will) so we believe that our scheme gives a way to trade off between the accuracy needed for medical diagnosis and the information reduction needed for st...

2002
S Nikneshan

This paper describes a new approach to Fixed rate Entropy coded Vector Quanti zation FEVQ for stationary memoryless sources where the structure of code words are derived from a variable length scalar quantizer We formulate the quantization search operation as a zero one integer optimization problem and show that the resulting integer program can be closely approximated by solving a simple linea...

1996
Jill McCabe Kristo Miettinen Joseph Reitz

The discrete wavelet transform has proven to be an effective technique for the compression of digital imagery at very low rates. This has lead to increasing interest in commercial, intemational, medical, and governmental arenas in the wide-spread use and standardization of this technology. As the popularity of wavelet based image compression systems grows, issues regarding the transmission of w...

2008
Mariusz H. Jakubowski João Ascenso Grzegorz Pastuszak

In some distributed video coding (DVC) systems, the total bitrate depends mainly on the key frames (Intra coded) quality and on the side information accuracy. In this paper, a rate control (RC) mechanism is proposed to achieve and maintain a certain target bitrate for the overall Intra and WZ bitstream, mainly by adjusting online the Intra frames quality through the quantization parameter (QP)....

2007
Chin Kiong Wang Gwenaël J. Doërr Ingemar J. Cox

Lattice codes and quantization-based techniques have received considerable attention as a method of digital watermarking with side information. However, these algorithms are also recognized to be highly sensitive to common signal processing primitives such as valuemetric scaling, e.g. changes in volume of a song, or re-quantization, e.g. JPEG compression. Hence, it is reasonable to investigate ...

Journal: :IEEE Trans. Information Theory 1996
Ram Zamir Meir Feder

We consider encoding of a source with a pre-speciied second order statistics, but otherwise arbitrary, by Entropy Coded Dithered (lattice) Quantization (ECDQ) incorporating linear pre-and post-lters. In the design and analysis of this scheme we utilize the equivalent additive noise channel model of the ECDQ. For Gaussian sources and square error distortion measure, the coding performance of the...

2007
Qian Xu

Layered Wyner-Ziv Video Coding: A New Approach to Video Compression and Delivery. (August 2007) Qian Xu, B.S., University of Science & Technology of China; M.S., Texas A&M University Chair of Advisory Committee: Dr. Zixiang Xiong Following recent theoretical works on successive Wyner-Ziv coding, we propose a practical layered Wyner-Ziv video coder using the DCT, nested scalar quantization, and ...

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