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Conference on Visual Communications and image Processing 2004

作者： Said, A Hewlett Packard Labs Cupertino CA 95014 USA

ISBN: (纸本)0819452114

It is possible to improve the features supported by devices with embedded systems by increasing the processor computing power, but this always results in higher costs, complexity, and power consumption. An interesting alternative is to use the growing networking infrastructures to do remote processing and visualization, with the embedded system mainly responsible for communications and user interaction. This enables devices to behave as if much more "intelligent" to users, at very low costs and power. In this article we explain how compression can make some of these solutions more bandwidth-efficient, enabling devices to simply decompress very rich graphical information and user interfaces that had been rendered elsewhere. The mixture of natural images and video with text, graphics, and animations simultaneously in the same frame is called compound video. We present a new method for compression of compound images and video, which is able to efficiently identify the different components during compression, and use an appropriate coding method. Our system uses lossless compression for graphics and text, and, on natural images and highly detailed parts, it uses lossy compression with dynamically varying quality. Since it was designed for embedded systems with very limited resources, and it has small executable size, and low complexity for classification, compression and decompression. Other compression methods (e.g., MPEG) can do the same, but are very inefficient for compound content. High-level graphics languages can be bandwidth-efficient, but are much less reliable (e.g., supporting Asian fonts), and are many orders of magnitude more complex. Numerical tests show the very significant gains in compression achieved by these systems.

关键词： embedded systems image and video coding mixed raster content remote visualization

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Origins of the Zigzag Scan in Transform-Based Picture coding 47

Origins of the Zigzag Scan in Transform-Based Picture Coding

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Conference on Applications of Digital image Processing XLVII

作者： Reznik, Yuriy A. Brightcove Inc Boston MA 02210 USA

ISBN: (纸本)9781510679344;9781510679351

We review the history of the development of one of the most iconic tools in image and video coding - the zigzag scan. Despite its simplicity, we will show that its development was a non-trivial process that took several years, multiple iterations, and multiple ideas that eventually led to the formation of its final "zigzag" shape. Remarkably, we also discover that early variants of the zigzag scan appeared before the invention of the DCT, intra-predictors, and many other techniques in image and video coding algorithms. It is one of the oldest and most fundamental techniques in this context. This paper also traces the evolution of image and video codec architectures over the last six decades and brings examples of uses of the zigzag scan in modern-era image and video coding standards.

关键词： image and video coding Fourier analysis Boas-Kac-Lukosz inequalities DFT DCT KLT zigzag scan

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A new partial codeword updating scheme based on rate-distortion optimization for adaptive vector quantization

A new partial codeword updating scheme based on rate-distort...

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IEEE International Conference on Multimedia and Expo (ICME 2007)

作者： Guo, Kai Po, Lai-Man City Univ Hong Kong Dept Elect Engn Kowloon Hong Kong Peoples R China

ISBN: (纸本)9781424410163

In this paper, we propose a new adaptive vector quantiza- tion (AVQ) algorithm based on the rate-distortion optimization. This algorithm employs a new partial codeword updating (PCU) scheme which achieves rate-distortion performance superior to that of the conventional AVQ algorithms using the full codeword updating (FCU) scheme. The PCU-AVQ only updates the codeword's components with the quantization error higher than an optimal threshold instead of replacing the whole codeword. Additionally, the mathematical relation between the Lagrangian multiplier and the approximate optimal threshold is devised to reduce the rate-distortion cost computation. The experimental results show that the proposed PCU-AVQ algorithm indeed improves the rate-distortion performance without much computational complexity penalty. The PCU-AVQ can be combined with transform coding and entropy coding for higher compression ratio, and it can be widely implemented in specific AVQ algorithms for image, video and speech coding.

关键词： adaptive vector quantization image and video coding rate-distortion optimization

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M-LTW:: A fast and efficient non-embedded intra video codec

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8th Pacific Rim Conference on Multimedia

作者： Lopez, O. Martinez-Rach, M. Pinol, P. Oliver, J. Malumbres, M. P. Miguel Hernandez Univ Avda Univ S-N Elche 03202 Spain Techn Univ Valencia E-46022 Valencia Spain

ISBN: (纸本)9783540772545

Intra video coding is a common way to process video material for applications like professional video editing systems, digital cinema, video surveillance applications, multispectral satellite imaging, HQ video delivery, etc. Most practical intra coding systems employ JPEG encoders due to their simplicity, low coding delay and low memory requirements. JPEG2000 is the main candidate to replace JPEG in this kind of applications due to the excellent R/D performance and high coding flexibility. However, its complexity and computational resources required for proper operation could be a limitation for certain applications. In this work, we propose an intra video codec, M-LTW, which is able to reach very good R/D performance results, as well as JPEG2000 or H.264 INTRA, with faster processing and lower memory usage.

关键词： image and video coding tree-based wavelet coding integer lifting transform low complexity coding

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MPEG-4 codec performance using a fast integer IDCT

MPEG-4 codec performance using a fast integer IDCT

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10th IEEE International Symposium on Consumer Electronics (ISCE 2006)

作者： Navarro, Antonio Silva, Antonio Tavares, Joao Univ Aveiro Inst Telecommun Univ Campus P-3800 Aveiro Portugal

ISBN: (纸本)1424402158

Several standardized video coding algorithms use a well known discrete cosine transform (DCT) at the encoder to remove redundancy from video random processes. Its inverse, the IDCT is present at the decoder as well as at the encoder loop. The accuracy of this inverse transform, required to avoid large drift between the encoder and decoder, is defined in an IEEE standard which will be withdrawn from MPEG and ITU standardized codecs. Due to the huge number of computations required to compute the FDCT/IDCT (Forward/Inverse DCT) pair, reduction of their complexity is essential to speed up the video processing. In this paper, we propose a fast integer IDCT calculation method. Additionally, we insert it into the MPEG-4 (Part 2) reference software in order to validate our proposed method. The testing results using two different video sequences, at QCIF resolution, show similar PSNR average values between the reference MPEG-4 and the proposed MPEG-4 codec.

关键词： fast 8x8-IDCT image and video coding MPEG-4

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Directional discrete cosine transforms: A theoretical analysis

Directional discrete cosine transforms: A theoretical analys...

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32nd IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Fu, Jingjing Zeng, Bing Hong Kong Univ Sci & Technol Dept Elect & Elect Engn Kowloon Hong Kong Peoples R China

ISBN: (纸本)9781424407286

Nearly all block-based transform techniques developed so far for image and video coding applications choose the 2-D discrete cosine transform (DCT) of a square block shape. With almost no exception, this conventional DCT is always implemented separately through two I-D transforms, along the vertical and horizontal directions, respectively. In one of our recent works, we have developed a directional DCT framework in which the first transform may choose to follow a direction other than the vertical or horizontal one, while the second transform is arranged to be a horizontal one. Compared to the conventional DCT, our directional DCT framework has been demonstrated to provide a better coding performance for image blocks that contain directional edges - a popular scenario in many image and video signals. In this paper, we attempt to pursue an in-depth theoretical analysis to understand how the coding gain is produced in the directional DCT framework and how big it can be.

关键词： image and video coding directional transforms coding efficiency

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Lattice vector quantization with reduced or without look-up table.

Lattice vector quantization with reduced or without look-up ...

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Visual Communications and image Processing 1998 Conference

作者： Rault, P Guillemot, C CCETT F-35510 Cesson Sevigne France

ISBN: (纸本)0819427497

This paper describes a new vector indexing algorithm for Lattice Vector Quantization, (LVQ). The technique applies to a large class of lattices such as Z(n), A(n), D-n or E-8, widely used in signal compression. Relying on a partitioning of the events sources, based on a notion of leaders as proposed in,(1) it allows to trade vector look-up table size for arithmetic operations. At the cost of a very small number of integer arithmetic operations, the algorithm leads to a very significant reduction of the vector look-up tables. This in turn leads to reduced encoder and decoder complexities. The introduction of the concept elf 'absolute' leaders, and of the corresponding coding and decoding algorithms, provides additional flexibility in trading table size for arithmetic operations. The association of these vector indexing techniques with product codes, in the framework of Lattice Vector Quantization, leads to increased compression performances.

关键词： lattice vector quantization vector indexing entropy coding data compression image and video coding

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Study of mutual scan-line fractal coding

Study of mutual scan-line fractal coding

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Conference on Visual Communications and image Processing 2003

作者： Limmaneepraserth, P Varakulsiripunth, R King Mongkuts Inst Technol Res Ctr Commun & Informat Technol Bangkok 10520 Thailand

ISBN: (纸本)0819450235

In this paper, we concentrate on mutual scan-line fractal coding (MSFC), which is a novel fractal coding approach, and its performance. The purposes of this study are to examine the advantages and disadvantages of the MSFC. The main idea of this approach is to make use of similarity of each imaging scan-line pair. In this method, the domain pool is designed by using equivalent property of two complete metric spaces. Then, the domain-range mapping, which is at the heart of iterated contractive transformation, is implemented with a pair of contractive affine transformations for generating mutual fractal codes. This method provides the small size of domain pools, thus speeding up the encoding time. The experimental results illustrate that the proposed approach can reduce both encoding and decoding times and also maintain coding efficiency in bit rate at the range of 1.2-2.5 bpp, without any entropy encoding at the end of the scheme.

关键词： mutual scan-line fractal coding self-similarity contractive transformation image and video coding

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Light-field image and video compression for future immersive applications

Light-field image and video compression for future immersive...

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作者： Antoine Dricot Telecom ParisTech

学位级别：博士

Evolutions in video technologies tend to offer increasingly immersive experiences. How- ever, currently available 3D technologies are still very limited and only provide uncom- fortable and unnatural viewing situations to the users. The next generation of immersive video technologies appears therefore as a major technical challenge, particularly with the promising light-field (LF) approach. The light-field represents all the light rays (i. e. in all directions) in a scene. New devices for sampling/capturing the light-field of a scene are emerging fast such as camera arrays or plenoptic cameras based on lenticular arrays. Several kinds of display systems target immersive applications like Head Mounted Display and projection-based light-field dis- play systems, and promising target applications already exist. For several years now this light-field representation has been drawing a lot of interest from many companies and institutions, for example in MPEG and JPEG groups. Light-field contents have specific structures, and use massive amounts of data, that repre- sent a challenge to set up future services. One of the main goals of this work is first to assess which technologies and formats are realistic or promising. The study is done through the scope of image/video compression, as compression efficiency is a key factor for enabling these services on the consumer markets. Secondly, improvements and new coding schemes are proposed to increase compression performance in order to enable efficient light-field content transmission on future networks.

关键词： light-field compression image and video coding

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Accelerating Transform Algorithm Implementation for Efficient Intra coding of 8K UHD videos

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ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 2022年第4期18卷 113-113页

作者： Guo, Yang Gao, Wei Ma, Siwei Li, Ge Peking Univ Sch Elect & Comp Engn Shenzhen 518055 Peoples R China Peng Cheng Lab Shenzhen 518055 Peoples R China Peking Univ Inst Digital Media Beijing Peoples R China

Real-time ultra-high-definition (UHD) video applications have attracted much attention, where the encoder side urgently demands the high-throughput two-dimensional (2D) transform hardware implementation for the latest video coding standards. This article proposes an effective acceleration method for transform algorithm in UHD intra coding based on the third generation of audio video coding standard (AVS3). First, by conducting detailed statistical analysis, we devise an efficient hardware-friendly transform algorithm that can reduce running cycles and resource consumption remarkably. Second, to implement multiplierless computation for saving resources and power, a series of shift-and-add unit (SAU) hardwares are investigated to have much less adoptions of shifters and adders than the existing methods. Third, different types of hardware acceleration methods, including calculation pipelining, logical-loop unrolling, and module-level parallelism, are designed to efficaciously support the data-intensive high frame-rate 8K UHD video coding. Finally, due to the scarcity of 8K video sources, we also provide a new dataset for the performance verification. Experimental results demonstrate that our proposed method can effectively fulfill the real-time 8K intra encoding at beyond 60 fps, with very negligible loss on rate-distortion (R-D) performance, which is averagely 0.98% Bjontegaard-Delta Bit-Rate (BD-BR).

关键词： image and video coding transform hardware architecture FPGA implementation ultra-high-definition (UHD) video 8K dataset

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