检索结果-内蒙古大学图书馆

A Distortion Optimal Rate Allocation Algorithm for Transmission of embedded Bitstreams over Noisy Channels

IEEE TRANSACTIONS ON COMMUNICATIONS 2008年第10期56卷 1581-1584页

作者： Banihashemi, Amir H. Hatam, Ahmad Carleton Univ BCWS Ctr Ottawa ON K1S 5B6 Canada Carleton Univ Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada

We propose a distortion optimal rate allocation algorithm for robust transmission of embedded bitstreams over noisy channels. The algorithm is based on the backward application of a Viterbi-like algorithm to a search trellis, and can be applied to both scenarios of fixed and variable channel packet length problems, referred to as FPP and VPP, respectively. For the VPP, the complexity of the algorithm is comparable to the welt-known dynamic programming approach of Chande and Farvardin. For the FPP, where no low-complexity algorithm is known, the complexity of the proposed algorithm is O(N-2), where N is the number of transmitted packets.

关键词： Combined source/channel coding distortion optimal rate allocation algorithm embedded bitstreams embedded coding joint source/channel coding progressively coded bitstreams trellis unequal error protection Viterbi algorithm

来源：评论

学校读者我要写书评

暂无评论

Degraded Broadcast Channel With Secrecy Outside a Bounded Range

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2018年第3期64卷 2104-2120页

作者： Zou, Shaofeng Liang, Yingbin Lai, Lifeng Poor, H. Vincent Shamai (Shitz), Shlomo Univ Illinois Coordinated Sci Lab Urbana IL 61801 USA Ohio State Univ Dept Elect & Comp Engn Columbus OH 43220 USA Univ Calif Davis Elect & Comp Engn Davis CA 95616 USA Princeton Univ Dept Elect Engn Princeton NJ 08544 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

The K-receiver degraded broadcast channel with secrecy outside a bounded range is studied, in which a transmitter sends K messages to K receivers, and the channel quality gradually degrades from receiver K to receiver 1. Each receiver k is required to decode message W-1, ... , W-k, for 1 <= k <= K, and to be kept ignorant of Wk+2, ... , W-K, for k = 1, ... , K - 2. Thus, each message Wk is kept secure from receivers with at least two-level worse channel quality, i.e., receivers 1, ... , k-2. The secrecy capacity region is fully characterized. The achievable scheme designates one superposition layer to each message with binning employed for each layer. Joint embedded coding and binning are employed to protect all upper-layer messages from lower-layer receivers. Furthermore, the scheme allows adjacent layers to share rates so that part of the rate of each message can be shared with its immediate upper-layer message to enlarge the rate region. More importantly, an induction approach is developed to perform Fourier-Motzkin elimination of 2K variables from the order of K-2 bounds to obtain a close-form achievable rate region. An outer bound is developed that matches the achievable rate region, whose proof involves recursive construction of the rate bounds and exploits the intuition gained from the achievable scheme.

关键词： Binning broadcast channel embedded coding multi-user secrecy capacity region

来源：评论

学校读者我要写书评

暂无评论

New compression paradigms in JPEG2000

New compression paradigms in JPEG2000

引用

Conference on Applications of Digital Image Processing XXIII

作者： Wu, GK Gormish, MJ Boliek, M Ricoh Silicon Valley Inc Menlo Park CA 94025 USA

ISBN: (纸本)0819437603

The JPEG2000 still image compression standard has adopted a new compression paradigm: "Encode once, decode many." JPEG2000 architecture allows the codestream to be decoded differently for different application needs. The codestream can be decoded to produce lossless and lossy images, specific spatial regions of the image or images with different quality and resolution. The syntax contains pointers and length fields which allow relevant coded data to be identified without the entropy coder or transforms. Consequently, the codestream can be "parsed" to create different codestreams without transcoding. For example, such parsing operation can create a new codestream which contains a lower resolution image (e.g. thumbnail) of the original codestream. If a codestream is produced appropriately, it can also be converted to codestreams of lower quality images, or images containing only a specific spatial region. This feature is very useful for many applications, especially on the internet.

关键词： JPEG2000 wavelet transform syntax marker embedded coding parser region of interest image compression standard ITU-T Rec. T.800 l IS 15544-1:2000

来源：评论

学校读者我要写书评

暂无评论

An embedded still image coder with rate-distortion optimization

An embedded still image coder with rate-distortion optimizat...

引用

Visual Communications and Image Processing 1998 Conference

作者： Li, J Lei, SW Sharp Labs Amer Camas WA 98607 USA

ISBN: (纸本)0819427497

It is well known that the fixed rate coder achieves optimality when all coefficients are coded with the same rate-distortion (R-D) slope. In this paper, we show that the performance of the embedded coder can be optimized in a rate-distortion sense by coding the coefficients with decreasing R-D slope, We denote such coding strategy as rate-distortion optimized embedding (RDE). RDE allocates the available coding bits first to the coefficient with the steepest R-D slope, i.e. the largest distortion decrease per coding bit. The resultant coding bitstream can be truncated at any point and still maintain an optimal R-D performance. To avoid the overhead of coding Order transmission, we use the expected R-D slope which can be calculated from the coded bits and are available in both the encoder and the decoder. With the probability estimation table of the QM-coder, the calculation of the R-D slope can be just a lookup table operation. Experimental results show that the rate-distortion optimization significantly improves the coding efficiency in a wide range of coding rates.

关键词： image coding embedded coding rate-distortion slope rate-distortion optimization scalability wavelet

来源：评论

学校读者我要写书评

暂无评论

embedded wavelet packet image coder with fast rate-distortion optimized decomposition

Embedded wavelet packet image coder with fast rate-distortio...

引用

1997 Conference on Visual Communications and Image Processing

作者： Li, J Kuo, CCJ Cheng, PY Univ. of Southern California (United States) Physical Optics Corp. (United States)

ISBN: (纸本)0819424358

A fast rate-distortion (R-D) optimized wavelet packet (WP) transform is proposed for image compression in this research. By analyzing the R-D performance of the quantizer and the entropy coder, we show that the coding distortion D can be modeled as an exponentially decaying function as the coding rate R increases. With this exponential R-D model, it is proved that the constant R-D slope criterion for optimum bit allocation is equivalent to the constant distortion criterion, which can be easily implemented via thresholding. Based on this analytical result, we develop a fast wavelet packet decomposition scheme which is optimized in the R-D sense by comparing simple parameters associated with each wavelet packet band such as the 1st or 2nd absolute moments. We have performed extensive experiments to demonstrate the performance of an image coder using the proposed R-D optimized wavelet packet transform, and shown that our scheme is highly competitive with all well known state-of-the-art image coders.

关键词： image compression rate-distortion wavelet packets wavelet coding embedded coding

来源：评论

学校读者我要写书评

暂无评论

Progressive coding of stereo images using a hybrid scheme

Progressive coding of stereo images using a hybrid scheme

引用

14th Stereoscopic Displays and Applications Conference/10th Engineering Reality of Virtual Reality Conference

作者： Palfner, T Müller, E Univ Rostock Inst Telecommun & Informat Technol D-18119 Rostock Germany

ISBN: (纸本)0819448060

In this paper, we propose a coder based on the Discrete Multiwavelet Transform, block-based disparity estimation and interpolation. By using the Discrete Multiwavelet Transform instead of the popular Discrete Cosine Transform we avoid artifacts which appear at low bit rates in the reconstructed stereo image and which do not only affect the subjective quality of each image individually, but also the depth perception. Our existing coder consists of an adapted state-of-the-art still image coder. The correlation between the two images is exploited by disparity compensation using overlapping blocks. Since the full-search block matching algorithm is very time-consuming, an interpolation factor of two has been used by our coder so far. However, to be able to improve the disparity compensation for certain images, our coder is upgraded by increasing the interpolation factor. To prevent an immense slow-down, faster search algorithms could be implemented. These faster algorithms can reduce the search space considerably. They do not give optimal compensation results, but in conjunction with a higher interpolation factors, they still can improve the performance. The results published in this paper are competitive.

关键词： stereo image discrete multiwavelet transform embedded coding

来源：评论

学校读者我要写书评

暂无评论

Improved SPIHT Algorithm 10

Improved SPIHT Algorithm

引用

International Conference on Signal-Image Technology and Internet-Based Systems SITIS

作者： Ochoa Dominguez, Humberto de Jesus Cruz Sanchez, Vianey Guadalupe Vergara Villegas, Osslan Osiris Univ Autonoma Ciudad Juarez Dept Elect & Comp Engn Ciudad Juarez Chihuahua Mexico Univ Autonoma Ciudad Juarez Dept Ind & Mfg Engn Ciudad Juarez Chihuahua Mexico

ISBN: (纸本)9781479979783

An improved SPIHT algorithm that combines the SPIHT and the subbands threshold calculation to reduce the number of comparison operations, without sacrificing the reconstructed image quality, is proposed. After applying discrete wavelet transform to the image, the threshold of each independent subband is calculated. The scanning of the sets inside a subband is determined by the magnitude of the thresholds that establish a hierarchical scanning not only for the set of coefficients with large magnitude, but also, for the subbands. The proposed algorithm uses the set partitioning technique to sort the transformed coefficients. Results show that the proposed algorithm significantly reduces the number of comparison operations in the sorting passes while maintaining the visual quality and PSNR of the recovered image.

关键词： Image processing image coding SPIHT transform coding embedded coding

来源：评论

学校读者我要写书评

暂无评论

embedded CELP WITH ADAPTIVE CODEBOOKS IN ENHANCEMENT LAYERS AND MULTI-LAYER GAIN OPTIMIZATION

EMBEDDED CELP WITH ADAPTIVE CODEBOOKS IN ENHANCEMENT LAYERS ...

引用

IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Stachurski, Jacek Texas Instruments Inc DSP Solut R&D Ctr Dallas TX 75265 USA

ISBN: (纸本)9781424423538

The paper describes an embedded CELP coder in which an adaptive codebook is included in every enhancement layer and the lower-layer codebook gains are re-optimized in the higher layers to further improve speech quality. Each layer maintains its own filter memories to generate required target vectors, adds adaptive and fixed codebook contributions, and re-optimizes all codebook gains to improve coder performance (multi-layer gain optimization). The common elements across the embedded layers include the lower-layer adaptive and fixed codebook entries. The pitch-lag used in the core layer is also re-used in the enhancement layers to maintain time synchronization between layers. Estimation and encoding of selected lower-layer parameters may take into account their estimated impact on the higher layers. The described embedded CELP coder has been implemented in the embedded Variable Bit-Rate (EV-VBR) codec standardized by ITU-T as Recommendation G.718. The characterization test results of the G.718 embedded CELP are summarized.

关键词： Speech coding embedded coding Scalable coding CELP

来源：评论

学校读者我要写书评

暂无评论

An Efficient SPIHT Algorithm and System Architecture for Image Compression 25

An Efficient SPIHT Algorithm and System Architecture for Ima...

引用

25th Signal Processing and Communications Applications Conference (SIU)

作者： Cekli, Serap Akman, Ali Maltepe Univ Bilgisayar Muhendisligi Istanbul Turkey

ISBN: (纸本)9781509064946

In this study, an efficient modified SPIHT algorithm and related architecture design is proposed for image compression. The proposed architecture is designed as a three stage pipeline structure. Different sized images are compressed using the designed architecture for different bpp values. The computed PSNR values of the compressed images using the proposed algorithm and also the original algorithm is compared in order to test the performance of the proposed algorithm and architecture.

关键词： wavelet transform image compression SPIHT coding algorithm embedded coding pipeline

来源：评论

学校读者我要写书评

暂无评论

Temporal sampling and spatial coding for rate control of video transmission on mobile cameras

Temporal sampling and spatial coding for rate control of vid...

引用

IEEE International Conference on Control Applications Part of 2010 IEEE Multi-Conference on Systems and Control

作者： Kuo, Chien-Ting Chen, I-Iming Lian, Feng-Li Lin, Yi-Chun Jean, Jong-Hann Natl Taiwan Univ Dept Elect Engn Taipei 10617 Taiwan St Johns Univ Dept Elect Engn Taipei Taiwan

ISBN: (纸本)9781424453634

The paper proposes a receiver-based, rate and quality control mechanism. The main principle is to regulate encoding rate to guarantee the video quality is acceptable, especially in region of interest. Transmitting the encoded bit stream in multicast delivery not only improves bandwidth efficiency but also provides different quality for receivers with different length of bit stream. The overall mechanism can be separated into temporal sampling and spatial coding. Temporal sampling chooses the clearest frame to reduce the cost of encoding and transmitting blur or similar frame. On the spatial coding, embedded coding is performed to discard partial wavelet coefficients to provide multi-resolution of the frame. Experimental results show that the correctness of moving object detection in mobile cameras. Besides, the quality of received video and the bandwidth efficiency under different bandwidth limitation are also analyzed.

关键词： Surveillance systems real-time video transmission rate control moving object detection embedded coding region of interest

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：