JPEG 2000--新的静止图像压缩标准

为满足不同应用需求而制定的新的静止图像压缩标准——JPEG2000已于2000年12月正式成为国际标准，对JPEG2000进行了系统的分析，对其采用的许多新算法及关键技术进行了详细的描述，包括基于提升法的第2代小波变换，位平面编码，自适应算术编码，标识树编码，感兴趣区域编码及基于渐进顺序的码流组织方式等。     

基于DICOM标准的大型医学影像分布式存储系统研究

提出了一种符合DICOM标准的大型医学影像分布式存储系统的体系结构。采用多级分布式存储体系，引入JPEG2000压缩技术，结合大型数据库，实现智能、稳定和高效的存储管理。切实解决了医院影像中心PACS目前和未来对大容量／超大容量医学影像数据存储的需求。     

Design and development of a secure DICOM-Network Attached Server

It is not easy to connect a web-based server with an existing DICOM server, and using a web-based server on the INTERNET has risks. In this study, we designed and developed the secure DICOM-Network Attached Server (DICOM-NAS) through which the DICOM server in a hospital-Local Area Network (LAN) was connected to the INTERNET. After receiving a Client's image export request, the DICOM-NAS sent it to the DICOM server with DICOM protocol. The server then provided DICOM images to the DICOM-NAS, which transferred them to the Client using HTTP. The DICOM-NAS plays an important role between DICOM protocol and HTTP, and only temporarily stores the requested images. The DICOM server keeps all of the original DICOM images. When unwanted outsiders attempt to get into the DICOM-NAS, they cannot access any medical images because these images are not stored in the DICOM-NAS. Therefore, the DICOM-NAS does not require large storage, but can greatly improve information security.     

一种保持码流结构的JPEG2000加密算法

本文提出了一种JPEG2000包体数据加密算法,通过可逆整数S变换处理加密后的包体数据,保证了不会产生新的标记码,因而原码流的结构及特性被保留了下来,压缩率也没有发生改变.加密后的码流仍能被标准解码器解码,但解读出来的是内容被完全掩蔽的无意义的图像.对256×256的Lena灰度图像进行加密实验,结果显示,该算法可以有效地保障加密图像的安全.     

Study on the technology of medical image reading based on JPEG2000

Along with the development of health informatization, many hospitals have set up PACS systems for centralized storage of patients’ medical examination images. Due to the large amount of image data, traditional methods such as C-MOVE, have slow upload and download speeds. And they also have security problems. Based on the research and development of medical imaging informatics and PACS, a JPEG2000-based method is described according to the PACS work flow and DICOM standard. This method makes the image storage, transmission and display operating in parallel, providing a good solution to timeliness and security problems of image reading and viewing.     

Implementation of a dynamic platform-independent DICOM-server

Hospital-wide image and patient data transfer within heterogeneous hard- and software infrastructures can be facilitated by using standardized communication protocols and data formats such as digital imaging and communications in medicine (DICOM). Each DICOM application entity (AE) usually provides a static and fixed set of services according to its functionality. However, certain security concepts, changing demands of medical users, or restricted hardware capabilities may be more easily addressed by applications that dynamically provide variable subsets of DICOM services. In a new approach, an object-oriented DICOM server framework was developed that served as a basis for assembling various DICOM applications. These applications may be set up dynamically to offer variable subsets of services at runtime, similar to "plug-ins". The framework was designed and implemented in Java in order to provide low-cost platform-independent solutions. As an example, a DICOM server was implemented and tested in a clinical application providing access to MR and CT images through a Java/DICOM viewer. Data retrieval was optimized by storing parts of the image acquisition and patient data into a relational database.     

基于JPEG2000的静态医学图像压缩设计方案

针对静态医学图像压缩，介绍了两种压缩标准JPEG与JPEG2000，通过对它们的比较，突出JPEG2000的优势，诠释了JPEG2000的基本结构与编码、解码技术，描述了基于DSP的图像压缩设计方案。系统采用CCD采集数字图像，用16位定点DSP进行小波压缩，主要为了减小传输费用，试验结果表明JPEG2000对图像重现与压缩比率效果较优。     

应用TMS320C5402实现DICOM3.0协议的PCI接口卡

首先简要介绍了DICOM3．0协议的组成以及激光相机的通信协议，然后根据实际情况对JPEG的自适应算法进行了推导，这种方法在不增加任何附加信息的基础上， 根据输出图像的频域分布，自适应地改变量化等级数,使医学图像信息在一定的压缩比下保留更多的图像细节。最终在对系统的可行性进行研究的基础上，应用TI公司生产的TMS320C5402实现了DICOM3．0的PCI接口卡。系统运行结果表明：该系统可对来自医疗影像设备的图像，实时稳定地转换为DICOM文件，并通过PCI总线存入计算机。该设计有较强的实用性，是PACS中的核心部分。     

An efficient hardware implementation of parallel EBCOT algorithm for JPEG 2000

With the augmentation in multimedia technology, demand for high-speed real-time image compression systems has also increased. JPEG 2000 still image compression standard is developed to accommodate such application requirements. Embedded block coding with optimal truncation (EBCOT) is an essential and computationally very demanding part of the compression process of JPEG 2000 image compression standard. Various applications, such as satellite imagery, medical imaging, digital cinema, and others, require high speed and performance EBCOT architecture. In JPEG 2000 standard, the context formation block of EBCOT tier-1 contains high complexity computation and also becomes the bottleneck in this system. In this paper, we propose a fast and efficient VLSI hardware architecture design of context formation for EBCOT tier-1. A high-speed parallel bit-plane coding (BPC) hardware architecture for the EBCOT module in JPEG 2000 is proposed and implemented. Experimental results show that our design outperforms well-known techniques with respect to the processing time. It can reach 70 % reduction when compared to bit plane sequential processing.     

DICOM数据集研究和DICOM图像处理软件的实现

针对DICOM3.0标准,详细分析了DICOM文件结构及DICOM数据集,给出了其中一些关键技术问题及相应的解决措施。最后基于VC.Net2003开发出一种DICOM医学图像处理软件,该软件能实现DICOM医学图像的显示、测量以及与通用图像格式转换等功能。     

分布式PACS中DICOM图像存取服务的设计与实现

分布式PACS相对于基于DICOM网络的传统PACS在系统结构和性能上有较大改进,但DICOM标准的专业性和复杂性严重阻碍了分布式PACS性能的提升。DICOM图像存取服务屏蔽了底层DICOM通讯协议和数据结构的复杂性,并通过为分布式PACS中的上层服务和外部应用提供一套IDL接口和访问机制来完成对DICOM图像文件中各类数据的访问,较大地提高了分布式PACS系统的开放性和互联互操作性。     

JPEG2000的编码技术

随着多媒体技术应用的不断增加，人们对图像压缩技术也提出了更高的要求。为此，国际标准化组织(ISO)指定了新一代静止图像压缩标准：JPEG2000。该文首先阐述了JPEG2000图像编码系统的实现过程，对其中的关键技术做了详细描述。最后。在与JPEG标准比较的基础上，分析了JPEG2000算法的特点,并给出了详细的试验结果。     

基于JPEG 2000实时量化水印和指纹识别的身份认证系统

提出了新的JPEG2000实时量化水印算法,并将其用于改进的基于指纹识别和数字水印的银行养老金发放系统。系统客户端,量化水印在JPEG2000压缩过程中实时嵌入指纹图像,压缩比特流传送到服务端;系统服务端,水印在JPEG2000解压缩过程中实时提取,使用解压缩的指纹图像和水印进行身份认证。实验表明典型指纹图像压缩到1/4~1/20的时候,嵌入的水印能够无损提取,指纹图像虽不能完全恢复但识别率没有明显降低。因而在低网络带宽条件下,新系统有更好的交互性能,在电子商务中有很好的应用前景。     

A service based approach for medical image distribution in healthcare Intranets

The Digital Imaging and Communications in Medicine (DICOM) protocol is currently the ubiquitous standard for the communication of medical images and related data within the radiology department. However, seamless image distribution within the healthcare enterprise and especially with research and educational information systems is still hard to achieve, as software developers of such third-party applications have to go through the rather cumbersome task of adapting the DICOM communication model and implementing the DICOM protocol. This paper gives a brief outline of current trends in medical image distribution in the healthcare enterprise, and proposes a new technological approach for distributing DICOM images and related data through commonplace Internet technologies, based on the emerging web services software paradigm. In particular, the paper describes the DICOM Image Management (DIM) web service which acts as a fa?ade for conventional DICOM sources allowing DICOM image data and related information, to be transformed into XML documents encapsulated in SOAP messages, enabling integration at the application level through general purpose standardized web technologies. Implementation issues are discussed and a demonstration of engaging the DIM web service is included.     

一种基于JPEG2000的医学图像感兴趣区域编码技术

感兴趣区域编码是静态图像压缩标准JPEG2000支持的一种非常重要的功能,该标准提供了两种感兴趣区域编码的方法,这两种方法用于医学图像的处理却存在不同的不足之处。该文结合这两种编码方法各自的优点,提出了一种分步位移的处理方法,该方法不仅支持多个感兴趣区域的编码,而且还能自由调整感兴趣区与背景区图像的压缩质量。实验结果表明,医学图像的压缩性能得到了明显的改善。     

基于JPEG/JPEG2000相结合的医学图像感兴趣区域压缩

提出了一种基于JPEG/JPEG2000相结合的医学图像感兴趣区域压缩方法.该方法对在人为选定医学图像的感兴趣区域采用无损的JPEG2000压缩,而对其他图像区域则采用高压缩比的JPEG压缩,从而较好地解决了医学图像的高压缩比和高质量之间的矛盾.通过对一副人脑MRI医学图像的压缩实验,得到了压缩比12:1,并且病灶区图像信息完整的压缩图像.     

Internet transmission of DICOM images with effective low bandwidth utilization

Progressive transmission of medical images through Internet has emerged as a promising protocol for teleradiology applications. The major issue that arises in teleradiology is the difficulty of transmitting large volume of medical data with relatively low bandwidth. Recent image compression techniques have increased the viability by reducing the bandwidth requirement and allowing cost-effective delivery of medical images for primary diagnosis. This paper highlights a wavelet based set partitioning in hierarchical trees (SPIHT) coder for progressive transmission of DICOM images. The header of the DICOM image is first transmitted followed by the compressed image data and then at the receiving end, images are reconstructed from low quality to high (or perfect) quality. The performance of the coder is evaluated using two image quality assessment criteria, namely, mean squared error (MSE) and mean structural similarity (MSSIM) index. The results prove that our method provides diagnostically useful information as rapidly as possible utilizing minimum bandwidth than variants of JPEG as reported in literature.     

基于DICOM标准的胶片扫描处理系统的实现

我国目前还存在许多非DICOM标准接口的医疗影像设备，这些设备中大部分仍然只是输出胶片。为了将这些胶片转换为符合DICOM标准的格式文件，然后将这些文件归档，该文介绍了一个胶片扫描处理系统的实现方法。在该系统中将X光胶片等用胶片扫描仪进行扫描，生成胶片的数字图像数据，然后将图像数据和输入的相关信息合并，构造出符合DICOM标准的文件，最后将文件传送到DICOM服务器。     

DICOM文件头信息读取及解析

DICOM作为医学图像存储和传输的标准,涵盖了医学数字图像的采集、归档、通信、显示及查询等几乎所有信息交换的协议,并且结构化地定义了医疗图像设备制造厂商的兼容性申明.通过分析DICOM文件的构成,解析DICOM文件头的组成和内容,实现对DICOM文件头的信息读取,并利用所获得的信息,进一步读取DICOM文件中的数据集存储内容,是读取DICOM文件的基本解析过程,可以将对DICOM文件的读取,从程序开发商的集成平台中分离出来,在结合图像显示程序之后,作为独立的DICOM文件读取程序使用.     

JPEG2000图像编码综述

随着科学技术的不断发展,为保证图像的实时数据传输,传统的JPEG标准开始不能满足实际应用的需要,新一代静止图像压缩JPEG2000应运而生。通过阐述JPEG2000图像压缩编解码的原理,并与传统的JPEG标准比较,分析JPEG2000的优点和存在的不足,为提高获取图像数据的实时传输性能提供理论依据。