JPEG(Joint Photographic Expert Group,联合摄影专家组)编码的数据执行解压缩的各项功能.JPEG的VHDL实现代码
标签： JPEG Photographic Expert Group
上传时间： 2016-12-23
上传用户：熊少锋
JPEG2000是由ISO/ITU-T组织下的IEC JTC1/SC29/WG1小组制定的下一代静止图像压缩标准.与JPEG(Joint Photographic Experts Group)相比,JPEG2000能够提供更好的数据压缩比,并且提供了一些JPEG所不具有的功能[1].JPEG2000具有的多种特性使得它具有广泛的应用前景.但是,JPEG2000是一个复杂编码系统,目前为止的软件实现方案的执行时间和所需的存储量较大,若想将JPEG2000应用于实际中,有着较大的困难,而用硬件电路实现JPEG2000或者其中的某些模块,必然能够减少JPEG200的执行时间,因而具有重要的意义.本文首先简单介绍了JPEG2000这一新的静止图像压缩标准,然后对算术编码的原理及实现算法进行了深入的研究,并重点探讨了JPEG2000中算术编码的硬件实现问题,给出了一种硬件最优化的算术编码实现方案.最后使用硬件描述语言(Very High Speed Integrated Circuit Hardware Description Language,VHDL)在寄存器传输级(Register Transfer Level,RTL描述了该硬件最优化的算术编码实现方案,并以Altera 20K200E FPGA为基础,在Active-HDL环境中进行了功能仿真,在Quartus Ⅱ集成开发环境下完成了综合以及后仿真,综合得到的最高工作时钟频率达45.81MHz.在相同的输入条件下,输出结果表明,本文设计的硬件算术编码器与实现JPEG2000的软件:Jasper[2]中的算术编码模块相比,处理时间缩短了30﹪左右.因而本文的研究对于JPEG2000应用于数字监控系统等实际应用有着重要的意义.
上传时间： 2013-05-16
上传用户：671145514
本文以“机车车辆轮对动态检测装置”为研究背景，以改进提升装置性能为目标，研究在Altera公司的FPGA(Field Programmable Gate Array)芯片Cyclone上实现图像采集控制、图像处理算法、JPEG(Joint Photographic Expert Group)压缩编码标准的基本系统。本文使用硬件描述语言Verilog，以RedLogic的RVDK开发板作为硬件平台，在开发工具OUARTUS2 6.0和MODELSIM SE 6.1B环境中完成软核的设计与仿真验证。 数据采集部分完成的功能是将由模拟摄像机拍摄到的图像信号进行数字化，然后从数据流中提取有效数据，加以适当裁剪，最后将奇偶场图像数据合并成帧，存储到存储器中。数字化及码流产生的功能由SAA7113芯片完成，由FPGA对SAA7113芯片初始化设置、控制，并对数字化后的数据进行操作。 图像处理算法部分考虑到实时性与算法复杂度等因素，从装置的图像处理流程中有选择性地实现了直方图均衡化、中值滤波与边缘检测三种图像处理算法。 压缩编码部分依据JPEG标准基本系统顺序编码模式，在FPGA上实现了DCT(Discrete Cosine Transform)变换、量化、Zig-Zag扫描、直流系数DPCM(Differential Pulse Code Modulation)编码、交流系数RLC(Run Length code)编码、霍夫曼编码等主要步骤，最后用实际的图像数据块对系统进行了验证。
上传时间： 2013-04-24
上传用户：qazwsc
DIGITAL IMAGERY is pervasive in our world today. Consequently, standards for the efficient representation and interchange of digital images are essential. To date, some of the most successful still image compression standards have resulted from the ongoing work of the Joint Photographic Experts Group (JPEG). This group operates under the auspices of Joint Technical Committee 1, Subcommittee 29, Working Group 1 (JTC 1/SC 29/WG 1), a collaborative effort between the International Organization for Standardization (ISO) and International Telecommunication Union Standardization Sector (ITUT). Both the JPEG [1–3] and JPEG-LS [4–6] standards were born from the work of the JPEG committee. For the last few years, the JPEG committee has been working towards the establishment of a new standard known as JPEG 2000 (i.e., ISO/IEC 15444). The fruits of these labors are now coming to bear, as JPEG-2000 Part 1 (i.e., ISO/IEC 15444-1 [7]) has recently been approved as a new international standard.
标签： Consequently efficient pervasive standards
上传时间： 2013-12-21
上传用户：源弋弋
We’re living through exciting times. The landscape of what computers can do is changing by the week. Tasks that only a few years ago were thought to require higher cognition are getting solved by machines at near-superhuman levels of per- formance. Tasks such as describing a Photographic image with a sentence in idiom- atic English, playing complex strategy game, and diagnosing a tumor from a radiological scan are all approachable now by a computer. Even more impressively, computers acquire the ability to solve such tasks through examples, rather than human-encoded of handcrafted rules.
标签： Deep-Learning-with-PyTorch
上传时间： 2020-06-10
上传用户：shancjb
