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1.
传统的基于二维小波变换的图像压缩方法在对高光谱图像细节部分进行量化编码时对低频部分进行全域矢量分解,噪点处理不够平滑,处理结果不好。提出一种改进的基于小波域子矢量的光谱图像压缩处理算法,对小波域的子矢量细节部分采用误差补偿编码的方法对高光谱图像的噪点进行平滑处理,对N级码书进行两级小波变换提取低频系数,通过算术编码实现城市、植被、水流多源信息高光谱图像压缩和解码恢复识别结果。仿真结果表明,采用该算法进行光谱图像压缩,图像经压缩处理后的恢复质量品质较高,峰值信噪比提高明显。  相似文献   

2.
针对高光谱图像带来的大量数据存储和传输的问题,本文提出了一种基于稀疏张量分解的高光谱图像压缩方法。首先,将高光谱图像作为三阶张量进行分析。其次,通过核心张量和压缩比的关系进行张量分解。最后,对数据进行稀疏编码处理。实验结果证明本文方法相对于现有方法来说,重构图像可以获得更高的信噪比,压缩时间更短,具有更好的压缩效果。  相似文献   

3.
将 Julia曲线"按正方形形状以多种方式进行量化,并将量化的 Julia曲线 "用于分形图像压缩编码,改变了分形图像压缩编码以变化的压缩编码字典进行编码的缺点。此外,还建立了一个小型的常用字典,用以加速分形图像的压缩编码。实验结果表明, Julia曲线 "能很好地拼贴所要编码的图像,并具有分形图像的解码优点。  相似文献   

4.
小波变换作用在图像上主要体现在两点:图像压缩和图像降噪。本文借用matlab这门科学和工程计算中常用的处理软件以及二维小波变换的分解和重构原理,实现了对原始图像的第一、二次压缩,并和单分辨率小波重构的效果图作了比较。  相似文献   

5.
随着多媒体技术的快速发展,静止图像的应用越来越广泛。它的应用主要集中在图像的存储和图像的传输两方面。本文首先介绍了静止图像压缩技术,介绍了基于离散余弦变换的JPEG图像压缩编码算法。鉴于数字图像的噪声模型,针对含有噪声的数字图像去除相关性比较差的问题,对图像作去噪处理后再用静止图像压缩标准JPEG作图像压缩编码。通过MATLAB仿真实验,表明先过滤再压缩的压缩方案信噪比比较高,压缩比的性能也可以达到良好。  相似文献   

6.
文章在研究近年来图像压缩一般方法的基础上,介绍了基于DCT变换的图像压缩的基本原理及其实现步骤。并使用MATLAB,针对不同量化步长对同一幅原始图像进行压缩,给出了实验仿真结果。  相似文献   

7.
干涉SAR图像数据压缩   总被引:1,自引:0,他引:1  
研究干涉SAR图像数据压缩问题,提出将干涉SAR的数据压缩转化为一个幅度图像的压缩和一个干涉相位图的压缩.设计机上信号处理流程,给出基于DCT和DWT的2种机上数据压缩方法,并对其数据压缩性能进行分析.针对相干斑对干涉相位影响较大的问题,在对干涉相位图进行压缩前,插入回转中值滤波.不同信噪比下干涉SAR仿真数据和实际数据的处理结果,表明了本文方法的有效性.  相似文献   

8.
本文首先将原始的高分辨率图像进行空域的下采样,将高分辨率图像转化为低分辨率图像后,再对低分辨率图像进行压缩感知采样,最后可以对重建后的低分辨率图像进行插值重建后得到高分辨率的图像。该方法复杂度都较低,实现了高效的图像压缩。  相似文献   

9.
侯佳欣  宋宇 《内江科技》2008,29(5):107-108
针对基于FPGA器件实现实时视频图像处理中原始视频数据与视频编码算法不兼容的问题,本文提出了一种离散缩放算法,通过它对原始图像进行预处理,能使图像缩放后仍具有自然分明的边界,达到较为理想的视觉效果,可以更好地通过FPGA器件进行后来的视频图像压缩。  相似文献   

10.
提出一种基于域特征点预置乱熵编码的高保密性无线视频传输实现方法,基于计算机视觉库OpenCV处理,对域特征点进行相关,并对视频域特征点进行分离,形成原始域特征点库,采用预置乱算法对域特征点库进行置乱,使得域特征点库在不增加容量的情况下提高保密性,基于置乱后的域特征点库进行熵编码,实现高效压缩,兼顾视频保密性和压缩率要求。采用实际视频进行处理,结果显示,采用该方法进行无线视频加密传输,视频在相对保密性提高40%的情况下,压缩效率仅降低了1%,在高保密性无线视频传输中具有很好的应用价值。  相似文献   

11.
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.  相似文献   

12.
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China's science enterprise by making S&T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party's Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.  相似文献   

13.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

14.
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."  相似文献   

15.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

16.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

17.
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.  相似文献   

18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

19.
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.  相似文献   

20.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

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