In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First,...In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG （joint photographic experts group） compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective.展开更多
针对传统图像压缩比控制不精细及低维混沌系统保密性不高的问题,提出一种基于连续色调静态图像的无损或近无损压缩标准(JPEG-LS)压缩比控制的图像压缩加密算法。在深入分析JPEG-LS中失真控制参数Near对图像压缩比和重建质量的影响的基础...针对传统图像压缩比控制不精细及低维混沌系统保密性不高的问题,提出一种基于连续色调静态图像的无损或近无损压缩标准(JPEG-LS)压缩比控制的图像压缩加密算法。在深入分析JPEG-LS中失真控制参数Near对图像压缩比和重建质量的影响的基础上,首先,对光栅扫描的图像数据进行梯度处理;然后,比较梯度值与Near的大小关系以决定进入游程模式进行游长编码或常规模式进行Golomb编码;再次对三维Lorenz混沌系统生成的序列进行随机性处理,采用该序列作为密钥分别对游程模式、常规模式和全模式(游程和常规两种模式)下的压缩码流进行加密;最后,对Near进行实时动态调整,实现了对图像的压缩比精细控制且提高了保密性。仿真结果表明,所提算法能够实现良好的压缩比控制,且重建图像质量比线性压缩比控制算法提高了大约0.5 d B;同时算法安全性高,能够有效抵抗熵攻击、差分攻击、穷举攻击、统计攻击等多种攻击,且加密对压缩效率基本没有影响。展开更多
给出了一种在可编程片上系统(System on programmable chip,SOPC)中实现JPEG解码的IP核设计方案,将JPEG解码算法中大量的运算采用硬件实现,嵌入式处理器只参与很少的一部分工作,从而大大提高JPEG的解码速度。本文分析了JPEG解码的原理,...给出了一种在可编程片上系统(System on programmable chip,SOPC)中实现JPEG解码的IP核设计方案,将JPEG解码算法中大量的运算采用硬件实现,嵌入式处理器只参与很少的一部分工作,从而大大提高JPEG的解码速度。本文分析了JPEG解码的原理,使用硬件语言构建了Huffman解码、反量化、反离散余弦变换等模块,完成了JPEG解码器的设计。仿真和测试结果表明,使用SOPC设计的JPEG解码IP核具有高性能、高效率且使用灵活、低成本等特点。展开更多
This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline arc...This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline architecture and accelerator elements have been utilized to enhance the throughput capability.Improved parameters mapping schemes and resource sharing have been adopted for the purpose of low complexity and small chip die area.Module-level and fine-grained gating measures have been used to achieve a low-power implementation.It has been proved that these hardware-oriented optimization techniques make the encoder meet the requirements of the IP core implementation.The proposed optimization techniques have been verified in the implementation of the JPEG-LS encoder IP,and then validated in a real wireless endoscope system.展开更多
基金supported by the National Natural Science Foundation of China under Grant No. 60703087the Project of Science and Technology Department of Zhejiang Province under Grant No. 2010C31006 and No. 2011C21081
文摘In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG （joint photographic experts group） compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective.
文摘针对传统图像压缩比控制不精细及低维混沌系统保密性不高的问题,提出一种基于连续色调静态图像的无损或近无损压缩标准(JPEG-LS)压缩比控制的图像压缩加密算法。在深入分析JPEG-LS中失真控制参数Near对图像压缩比和重建质量的影响的基础上,首先,对光栅扫描的图像数据进行梯度处理;然后,比较梯度值与Near的大小关系以决定进入游程模式进行游长编码或常规模式进行Golomb编码;再次对三维Lorenz混沌系统生成的序列进行随机性处理,采用该序列作为密钥分别对游程模式、常规模式和全模式(游程和常规两种模式)下的压缩码流进行加密;最后,对Near进行实时动态调整,实现了对图像的压缩比精细控制且提高了保密性。仿真结果表明,所提算法能够实现良好的压缩比控制,且重建图像质量比线性压缩比控制算法提高了大约0.5 d B;同时算法安全性高,能够有效抵抗熵攻击、差分攻击、穷举攻击、统计攻击等多种攻击,且加密对压缩效率基本没有影响。
文摘给出了一种在可编程片上系统(System on programmable chip,SOPC)中实现JPEG解码的IP核设计方案,将JPEG解码算法中大量的运算采用硬件实现,嵌入式处理器只参与很少的一部分工作,从而大大提高JPEG的解码速度。本文分析了JPEG解码的原理,使用硬件语言构建了Huffman解码、反量化、反离散余弦变换等模块,完成了JPEG解码器的设计。仿真和测试结果表明,使用SOPC设计的JPEG解码IP核具有高性能、高效率且使用灵活、低成本等特点。
基金Supported by National High Technology Research and Development Program (No.2008AA010707)
文摘This paper presents the key optimization techniques for an efficient accelerator implementation in an image encoder IP core design for real-time Joint Photographic Experts Group Lossless(JPEG-LS) encoding.Pipeline architecture and accelerator elements have been utilized to enhance the throughput capability.Improved parameters mapping schemes and resource sharing have been adopted for the purpose of low complexity and small chip die area.Module-level and fine-grained gating measures have been used to achieve a low-power implementation.It has been proved that these hardware-oriented optimization techniques make the encoder meet the requirements of the IP core implementation.The proposed optimization techniques have been verified in the implementation of the JPEG-LS encoder IP,and then validated in a real wireless endoscope system.
