基于MJPEG2000嵌入式网络视频采集压缩系统的设计与实现

本文设计了DSP ARM的独立双核结构的嵌入式视频压缩系统。该系统将采集到的连续视频序列按新一代图像压缩标准MJPEG2000压缩后，数据打包发送到网络。本文介绍了系统实现的原理和方法．重点介绍了如何高效地设计ARM与DSP之间的接口以满足嵌入式系统的实时性要求。试验结果表明，各项指标均达到设计要求。该系统为实现远程监控及视频网络传输等提供了解决方案。     

实时图像压缩存储系统的发展和应用

讨论了实时视频图像压缩系统产生的技术条件和背景,介绍了实时图像压缩的几个基本概念。讨论了编码的实现方法和它们的特点。介绍了图像压缩的发展过程和当前成熟的算法标准。在文章的最后给出了两个应用实例。     

基于ADV202的遥感图像实时压缩系统设计

提出了以JPEG2000图像压缩标准作为压缩算法,采用JPEG2000专用编解码芯片ADV202来实现遥感图像实时压缩系统的方案.该方案可以满足遥感图像压缩系统对实时性、低失真以及高压缩比的要求.测试结果表明,该系统工作稳定可靠,能够满足遥感图像压缩系统实时性的要求,图像压缩效果令人满意.     

OMAP5912双核通信及其数字音频系统实现

根据OMAP5912双核的特点,详细叙述了双核间通信的几种方式和基础应用程序.并以基于OMAP5912的数字音频系统为例,介绍OMAP双核问通信的具体应用.     

遥测图像压缩系统的设计与实现

遥测系统在传输图像数据时,通常要求图像遥测单元在尽量小的空间中较多地采集和传输图像信息,以提高图像质量和试验效率,减少系统研制成本。遥测图像压缩系统通过采用大规模FPGA和专用图像压缩芯片方法,在紧凑空间内,实现了遥测图像压缩系统的全部功能,节省了传输带宽,提高了系统的整体性能体积比。该遥测图像压缩系统已应用于具体试验,试验结果证明,遥测图像系统的设计可以满足系统的使用要求。     

基于NiosII的JPEG图像压缩系统平台设计

文中提出了一种基于NIOSII软核处理器的JPEG图像压缩系统平台的实现方法,主要介绍了SOPC技术以及NIOSII软核处理器的特点,并分别介绍了系统的硬件结构设计以及工作原理和JPEG图像压缩算法流程以及软件实现方法。采用该系统平台能够更加方便快捷的实现JPEG压缩算法的应用,而且可以根据图像压缩处理的要求,对系统进行灵活地裁减、扩充,真正实现了系统软硬件的可编程。     

FPGA实现高效实时图像压缩系统

本文提出了一种高效、压缩比在线可调的实时图像压缩系统方案,并且详细说明了硬件设计结构.与现有的结构相比,该结构具有并行度高,抗误码能力强等特点,图像质量可满足大多数应用要求.本系统中采用Xilinx最新推出的Virtex Ⅱ Pro系列产品中的XC2VP40来实现在FPGA上的设计.     

基于FPGA的M-JPEG实时编码器设计

针对在嵌入式系统中用软件进行压缩编码速度较慢的问题,设计一种基于FPGA的M-JPEG压缩处理结构.该结构充分利用FPGA的特点,提出用一个1D-DCT模块实现2D-DCT变换的新方法,并且根据M-JPEG基本原理,对图像处理算法做了一系列改进,使单幅320×240图像压缩的时间达到8.412 ms,满足了图像压缩的实时性要求.     

基于小波理论的视频图像压缩技术的研究与实现

将小波理论应用于视频图像的压缩是目前国内外十分重视的图像压缩技术。本文在深入研究以往图像压缩标准的基础上,针对小波理论的特点提出了一种适用于远程监控系统中视频图像压缩和传输的小波视频压缩方式。     

基于WMSNs的图像压缩技术研究

无线多媒体传感器网络(WMSNs)通过数量庞大的终端传感节点实现对外部环境的监测,并通过无线网络进行通信。随着外部环境的不断变化,对无线多媒体传感器网络的环境监测性能也提出了新的需求,如将各类多媒体资源加入到环境监测中,以获得更为细化精准的监测信息。文章综合分析了WMSNs图像压缩技术的研究发展现状,指出了现有的WMSNs图像压缩技术的不足以及应用WMSNs的图像压缩技术应满足的要求;并对图像压缩中的三种主要变换,即DCT变换、小波变换、双正交叠式变换(LBT)进行了分析比较。同时根据WMSNs的特点,提出了基于双正交重叠变换技术(LBT)的多节点协同图像压缩优化算法设计策略,有效解决了WMSNs的单节点图像处理功能受限问题。     

基于算术编码的异构双核SoC代码压缩方法

介绍了一种基于二进制算术编码和马尔可夫模型的代码压缩算法,并以此为基础,面向自主研发的异构双核SoC—GEM-SOC,提出了一种软件实现的解码方法。该方法可以根据不同应用的代码特点,选择合适的马尔可夫模型参数,从而达到最佳的代码压缩率。一组媒体应用测试表明,该方法可以显著减小双核SoC中DSP处理器的代码尺寸。     

双核处理视频压缩系统的设计与实现

针对目前视频处理平台单核运算、效率不高、升级不方便的特点，提出了DSP＋FPGA双核并行处理的新型体系结构，同时发挥DSP能够高速处理数字信号和FPGA善于控制大数据量吞吐的特性，快速有效地实时实现了CIF格式图像的H．264视频压缩算法；同时对H．264视频压缩标准的快速预测算法进行了研究，并针对DSP硬件及指令特点实现了代码优化．结果表明DSP＋FPGA双核联合使用，提高了系统执行效率和灵活性，在压缩速度和压缩质量上都取得了良好的效果．     

Speed-up fractal image compression with a fuzzy classifier

This paper presents a fractal image compression scheme incorporated with a fuzzy classifier that is optimized by a genetic algorithm. The fractal image compression scheme requires to find matching range blocks to domain blocks from all the possible division of an image into subblocks. With suitable classification of the subblocks by a fuzzy classifier we can reduce the search time for this matching process so as to speedup the encoding process in the scheme. Implementation results show that by introducing three image classes and using fuzzy classifier optimized by a genetic algorithm the encoding process can be speedup by about 40% of an unclassified encoding system.     

一种可重构数据压缩信息处理系统的设计实现

本文介绍可重构电子系统相关技术的发展现状,在分析了JPEG2000标准编解码芯片ADV212内部结构和工作原理的基础上,提出了一种可重构的数据压缩信息处理系统设计方案,它结合了FPGA器件的灵活性和专用图像数据编解码芯片的高效性,系统架构上主要运用FPGA资源实现系统重构,即运用可编程逻辑对图像数据压缩芯片ADV212进行寄存器配置、数据码流调度控制以及系统时序逻辑适配。经过图像数据的压缩解压对比测试,该数据压缩信息处理系统具有较高的峰值信噪比(PSNR),在实现了系统可重构同时,能够满足某型高速光通信系统对图像数据压缩实时性和数据完整性的要求。     

A differential index assignment scheme for tree-structured vectorquantization

A differential index (DI) assignment scheme is proposed for the image encoding system in which a variable-length tree-structured vector quantizer (VLTSVQ) is adopted. Each source vector is quantized into a terminal node of VLTSVQ and each terminal node is represented as a unique binary vector. The proposed index assignment scheme utilizes the correlation between interblocks of the image to increase the compression ratio with the image quality maintained. Simulation results show that the proposed scheme achieves a much higher compression ratio than the conventional one does and that the amount of the bit rate reduction of the proposed scheme becomes large as the correlation of the image becomes large. The proposed encoding scheme can be effectively used to encode MR images whose pixel values are, in general, highly correlated with those of the neighbor pixels.     

一种基于小波变换的低比特率混合图像编码方法

本文提出了一种基于小波变换的低比特率图像编码方法,利用人的视觉特性对高频高活跃度系数进行调制,为了保护图像能量,对高频高能系数进行标量量化后采用自适应算术编码,采用高分辨率级子图像矢量分类信息由低分辨率级子图像矢量自动产生,提高了压缩比。实验表明采用此编码方法在高压缩比的情况下获得了较好的图像质量。     

基于混沌序列的CCSDS图像压缩算法安全性扩展

CCSDS是由空间数据系统咨询委员会提出的,故针对空间飞行器应用的图像压缩算法,面向空间敏感图像传输的安全性需求,以及针对CCSDS图像压缩算法的特点,在不改变CCSDS算法流程和数据格式的基础上,利用混沌序列的随机性和不可预测性,在小波变换域对图像进行加密处理,以达到安全性扩展的目的。实验结果表明,该算法实现了较高的加密强度,同时保持了CCSDS算法高压缩比和低复杂度的优势,具有与CCSDS兼容性好,实现简单的优点。     

A hybrid scheme for low bit-rate coding of stereo images

We propose a hybrid scheme to implement an object driven, block based algorithm to achieve low bit-rate compression of stereo image pairs. The algorithm effectively combines the simplicity and adaptability of the existing block based stereo image compression techniques with an edge/contour based object extraction technique to determine appropriate compression strategy for various areas of the right image. Unlike the existing object-based coding such as MPEG-4 developed in the video compression community, the proposed scheme does not require any additional shape coding. Instead, the arbitrary shape is reconstructed by the matching object inside the left frame, which has been encoded by standard JPEG algorithm and hence made available at the decoding end for those shapes in right frames. Yet the shape reconstruction for right objects incurs no distortion due to the unique correlation between left and right frames inside stereo image pairs and the nature of the proposed hybrid scheme. Extensive experiments carried out support that significant improvements of up to 20% in compression ratios are achieved by the proposed algorithm in comparison with the existing block-based technique, while the reconstructed image quality is maintained at a competitive level in terms of both PSNR values and visual inspections.     

An Integrated Approach to Image Watermarking and JPEG-2000 Compression

A scheme which integrates image compression and image watermarking in an effective way is proposed in this research. The image compression scheme under consideration is EBCOT (Embedded Block Coding with Optimized Truncation) which has been adopted in the verification model (VM) of the emerging JPEG-2000 image compression standard. The watermark is embedded during the process when the compressed bit-stream is formed, and can be detected on the fly in image decoding. Thus, watermark embedding and retrieval can be done very efficiently in comparison with other existing watermarking schemes. In addition to efficiency, the proposed scheme has many interesting features. The embedded watermark is robust against various signal processing attacks such as coding and filtering while the watermarked image maintains good perceptual quality. The watermark retrieval procedure does not require the knowledge of the original image. Furthermore, the watermark can be detected progressively and region of interest (ROI) watermarking can be accomplished easily.