基于VBR视频的联合信源信道码率控制方法

VBR视频编码与传输相比于CBR具有更大的优势。VBR编码中,需要根据编解码缓冲区和网络的约束进行信源信道码率控制。本文将联合信源信道码率选择问题进行简化,针对最新的视频压缩标准H．264提出准确的码率模型,在此模型下进行VBR信源编码码率控制,并根据缓)中器状态进行信道传输速率选择来获得平滑的网络流量。实验结果表明,这种VBR码率控制方法比CBR可以获得更高和更平稳的视频质量,而且在场景切换时效果更明显。     

弱对偶基下比特并行RS编码器的设计

讨论了高速RS码编码器的设计问题。研究了有限域元素在弱对偶基（WDB）下的表示,基于弱对偶基下的最优弱对偶基的计算方法,给出了有限域比特并行乘法器的设计过程,并且利用这样的乘法器构成了广泛应用的RS（255,223）码的编码器。RS（255,223）码的编码器的复杂度定量的分析结果表明：弱对偶基下的比特并行乘法器设计复杂度降低,便于VLSI实现。编码器的数据吞吐率可达较高值,有利于高速应用场合。     

MPEG-2 视频编码器的硬件实现方法

目的 探讨一个实现数据压缩的脱机系统。方法 利用单芯片MPEG－2,借助FPGA技术对输入／输出数据进行必要的处理。结果 最终实现数据压缩的脱机系统。结论 MPEG－2图像编码是通信系统中最有效的编码方法,借助FPGA用单芯片实现MPEG－2编码已成为可能。     

A fast algorithm for polynomial evaluation in Reed-Solomon codec

An efficient lookup table algorithm for computing the values of message polynomials during high throughput encoding of Reed–Solomon (RS) codes is presented in this paper. The algorithm can be applied to RS codes encoders, which are based on Vandermonde matrix and the polynomial computations. The lookup table derived from the algorithm can then be applied not only to an encoder of RS codes but also to syndromes evaluation in the decoding of RS codes. By comparison with Horner’s rule, one of the advantages of utilizing this algorithm is that the table lookup operations for computing the values of the message polynomial are reduced by a factor of three. It would reduce the encoding time by fifty-percent using the linear feedback shift register to encode the (204, 188, t = 8) RS code. The algorithm can also be used to evaluate the syndromes needed in part of the RS decoder, and thus the speed is much faster than Horner’s rule. Ultimately, the proposed encoding and syndrome evaluation algorithm for RS codes can be made regular, simple and suitable for software implementations.     

超小型准绝对式编码器的研制

针对编码器日趋小型化的技术要求,本文提出一种全新的编码方式和独特的读数头设计结构,成功研制出了超小型准绝对式编码器.该新型编码器采用准绝对式编码方式,即距离编码与增量式编码进行组合编码,只用两圈码道进行编码,极大减少码道数量,整周设多个绝对参考位置,可迅速获得绝对位置信息.采用单读数头结构和相位补偿技术,缩小结构尺寸,直径Ф25 mm,经过电子学细分后可到达16位的分辨力,从而实现高精度编码器小型化.     

Analysis,design and implementation of sensorless <Emphasis Type="Italic">V/f</Emphasis> control in a surface-mounted PMSM without damper winding

This paper presents a novel, reliable and efficient V/f control implementation on a 8-pole, 750 rpm, 5 kW surface-mounted permanent magnet synchronous motor (PMSM) without damper winding. In the absence of a damper winding, open loop V/f control of SM is inherently unstable, particularly at high speeds. Stabilisation can be done with proper stator frequency modulation in accordance with the change in rotor speed to provide for effect of damping. This has been implemented here without use of any shaft-mounted encoder. The change in rotor speed is observed from power perturbation, thereby eliminating the need for using a speed sensor in the drive. The efficiency of the drive is further increased with appropriate control of the power factor, irrespective of load and frequency variations. Simulated and experimental results are presented for both open-loop and the proposed V/f control. These results establish the accuracy of the design of the proposed V/f control strategy and the precision of hardware implementation. A comparative study between the proposed V/f control method and standard vector control method, as implemented on this PMSM, has also been presented here to establish the advantages of the proposed scheme. The PMSM itself was designed and fabricated in the laboratory.     

Effect of different traversal schemes in integral image coding

Integral imaging (InIm) is a highly promising technique for the delivery of three-dimensional (3D) image content. During capturing, different views of an object are recorded as an array of elemental images (EIs), which form the integral image. High-resolution InIm requires sensors with increased resolution and produces huge amounts of highly correlated data. In an efficient encoding scheme for InIm compression both inter-EI and intra-EI correlations have to be properly exploited. We present an EI traversal scheme that maximizes the performance of InIm encoders by properly rearranging EIs to increase the intra-EI correlation of jointly coded EIs. This technique can be used to augment performance of both InIm specific and properly adapted general use encoder setups, used in InIm compression. An objective quality metric is also introduced for evaluating the effects of different traversal schemes on the encoder performance.     

CDPD系统中的RS编码器的改进设计

以CDPD系统中的RS（63，47）编码为例，对现有的Reed-Solomon编码器进行了改进优化设计，提出了一种利用对偶基上的改进乘法器来实现的编码器结构。该结构提高了编码的速度，节省了硬件资源，并具有一定的通用性，特别适合超大规模集成电路的实现。     

Architecture and implementation of the grand alliance HDTV video encoder

A high-definition television (HDTV) video compression encoder is being constructed for use during the standardization process for United States terrestrial broadcast HDTV. The encoder generates an MPEG-2 main profile/high level compliant bitstream at compressed data rates from 10–80 million bits/second. Both interlaced and progressive image formats in image sizes up to 1080 lines × 1920 pixels per line are supported.©1994 John Wiley & Sons Inc     

基于编码模式的H.264/AVC视频信息隐藏算法

本文提出一种基于编码模式的H.264/AVC信息隐藏方法,通过调制某些宏块的编码模式,分别在Ⅰ帧、P帧和B帧中嵌入隐秘信息.对帧内4x4预测模式的宏块,是通过调整宏块中某个4×4块的编码模式嵌入隐秘信息;对P帧和B帧其它类型的宏块,则是通过调整宏块的编码模式嵌入隐秘信息,模式调整后对宏块做了优化处理.在模式调制过程中引入率失真代价,取得了较好的率失真平衡,减小了隐秘信息嵌入后对视频质量和视频码流的影响.该算法可以实现隐秘信息的快速提取,满足视频实时处理的要求,实验仿真结果证明了该算法的有效性.     

低比转速高速液氮离心泵的设计与试验研究

以比转速为43的高速液氮离心泵为例阐述了低温高速离心泵的结构设计和水力设计方法。结构上采用金属波纹管密封和聚氨脂同步齿形带传动等结构形式，理论上采用水中短叶片相间的复合叶轮优化设计方法，水力试验和现场应用表明，提出了结构方案和设计方法合理可行。     

一种新型矩阵编码器的研究

针对编码器的小型化和高测量精度的技术要求,本文提出了一种新型绝对式矩阵编码器,它具有刻划圈数少,测量精度高等优点.本文主要进行了新型矩阵码盘设计、译码电路设计、精码校准和细分电路设计,应用Matlab软件进行仿真.实验结果表明,本文中设计的编码器实现了超小化,体积为中30 mm×15 mm,经过A/D细分,编码器分辨率...     

Multiple-phase retrieval for optical security systems by use of random-phase encoding

The technique of the multiple phase encoding for optical security and verification systems is presented in this paper. This technique is based on a 4-f optical correlator that is a common architecture for optical image encryption and verification systems. However, two or more phase masks are iteratively retrieved by use of the proposed multiple phases retrieval algorithm (MPRA) to obtain the target image. The convergent speed of the iteration process in the MPRA is significantly increased and the recovered image is much more similar to the target image than those in previous approaches. In addition, the quantization effects due to the finite resolution of the phase levels in practical implementation are discussed. The relationships between the number of phase masks and the quantized phase levels are also investigated. According to the simulation results, two and three phase masks are enough to design an efficient security verification system with 64 and 32 phase levels, respectively.     

基于图像传输的巡线机器人远程控制

基于无线局域网络的图像传输,从提高图像传输的实时性和连贯性着手,完成了巡线机器人远程控制方案的设计和实验。图像传输采用并行的处理方式,大大提高了传输的速度;分析了影响图像传输质量的因素,提出了增强图像传输品质和连贯性的方法,实现了在监控端根据图像方便地对机器人实施控制的设计,并通过实验验证了图像传输的实时性和远程控制方案的有效性。     

Efficient bit‐plane coding scheme for fine granular scalable video coding

In this paper, we propose a new efficient bit‐plane coding method for fine granular scalable (FGS) video coding. The general structure of the proposed bit‐plane coding method is based on the traditional bit‐plane coding scheme in MPEG‐4 FGS. However, to enhance coding efficiency of bit‐plane encoding, we apply an efficient probability estimation scheme through employing the binary arithmetic coding. For probability estimation, various context models are designed to take advantage of the characteristics of each bit‐plane as well as the correlations of symbols among different bit‐planes. Experimental results show that the proposed FGS coding scheme provides better coding performance, compared to the well‐known FGS coding schemes in MPEG‐4 FGS and JSVM. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 113–120, 2006.     

H.26L关键编码技术性能研究

H．26L的编码效率比已有的其他视频编码标准有很大的提高。在相同PSNR下与H．263和MPEG4相比，H．26L在低码率时的输出码率平均节省分别约为40％和36％，在高码率时的输出码率平均节省分别约为55％和45％。本文描述了H．26L的编码器结构框图，对各模块的作用和使用的技术进行了综述，并与其他视频标准中的主要技术进行了比较。对H．26L中几种技术在高、中和低码率下对编码效率的影响进行了实验研究并给出实验结果，这对于不同码率的视频应用时编码器的参数选择和模式选择有重要意义。     

一种基于旋转编码器的车辆行车状态无线监测装置

开发一种基于旋转编码器的车辆行车状态无线监测装置,采用增量式旋转编码器作为速度测量元件,基于STM32F103VET6处理器与嵌入式实时操作系统μC/OS-Ⅱ进行系统监测装置的软硬件设计。比较目前几种常用的车辆测速方式的优劣,叙述车辆行车状态无线监测装置的工作原理及其架构,速度测量元件、监测装置的软硬件子系统的设计要点,给出软件流程图和行车状态实时监测曲线。根据现场的实验测试表明:该系统不仅架构简单、使用方便,而且具有良好的实时性、可靠性和测速分辨率等。     

Optimal weighed Holoentropy for video compression: an advanced HEVC

ABSTRACT

In recent times, the applications of multimedia are rising in a greedy mode and hence the amount of video transactions is also increasing exponentially. This has shouted great demands on effective models on video encoding and also for reducing the transmission channel congestion. This research work introduces a managing technique termed weighted encoding for High-Efficiency Video Coding (HEVC). HEVC, also termed as MPEG-H Part 2 and H.265 is a video compression standard that is widely utilized AVC (H.264 or MPEG-4 Part 10). When compared to AVC, HEVC grants double the ratio of data compression at a similar level of quality of the video or considerably enhanced video quality at a similar bit rate. This work intends to optimize the weight that adopted in HEVC for encoding. For this, this paper proposes a new Iterative based propagation update in the water wave Optimization Algorithm (IPU-WWO), which is the improved form of Water wave Optimization (WWO). The performance of proposed IPU-WWO is compared over other conventional methods like Artificial Bee Colony (ABC), Firefly (FF), Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) with respect to Peak Signal to Noise Ratio (PSNR). By doing the encoding process, it minimizes the video size with perceptually better quality video or PSNR.     

An effective codebook search algorithm for vector quantization

Abstract

A new scheme that aims to cut down on the computational cost of the vector quantization (VQ) encoding procedure is proposed in this paper. In this scheme, the correlation between the codewords in the codebook is exploited and three test conditions are designed to filter out the impossible codewords in the codebook. The design of test conditions is based on the concept of integral projection.

From the experimental results, it is shown that the new scheme outperforms all the other schemes proposed so far in speeding up the VQ encoding procedure. When the codebook of 1024 codewords is used in the proposed scheme, the execution time it consumes is less than 2 per cent of that needed by the full search algorithm. The average time reduction rate is approximately 97.7 per cent compared to the execution time for the full search algorithm. In other words, the proposed scheme indeed provides an effective approach to speed up the VQ encoding procedure.     

H.264帧内预测与帧间块模式选择快速算法

针对H.264帧间预测时的多子块模式选择和帧内预测的多模式选择问题,提出了一种实用的基于统计门限的模式快速选择算法,通过门限设定有效限定了编码模式的选择范围.多组视频序列的实验结果表明,基于统计门限的帧内预测模式选择算法在Ⅰ帧的PSNR值有微小变化的情况下,大大降低了编码时间,Ⅰ帧的编码时间降低17%～23%,PSNR下降不到0.4%.基于统计门限的帧间块模式选择算法使得平均PSNR值下降了0.047dB(PSNR最大下降不到1%),但是相对全模式预测时,编码器速度提高了20%～30%.