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1.
双目立体视觉测距原理就是利用两台摄像机从两个视点获取目标点在不同视角下形成的图像坐标,利用成像几何模型计算同名像点图像坐标偏差,来获取目标点的三维坐标,从而实现距离测量,它在高速公路安全车距测量上有着极大的应用前景。当前的测距技术有主动测距法和被动测距法,论文采用的是基于OpenCV的被动测距法,得到摄像机标定的参数和立体匹配的对应特征点后,该测距算法较容易实现。经过实验验证,该算法在一定测量范围内达到精度要求。 相似文献
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《科技通报》2015,(8)
通过对人体心脏器官的医学图像重建,为实现三维可视化手术及图像重构提供图像基础。传统的心脏医学图像重建方法采用的是三维坐标点动态数据采集算法,当测量点相对散乱时无法满足心脏器官重建的准确性要求。提出一种融入背景差分连续重构的心脏医学图像重建方法,进行图像细节纹理的灰度化图像进行提升分离,定义表面渲染的选项,计算二维层状图像纹理特征像素点检测沿幅角方向上模值的极大值点,得到三维成像的仿真视景图像的质心位置,采用二阶累积泰勒展开算法,对三维图像模型进行心脏图像的纹理特征提取,实现算法改进。仿真结果得出,采用该算法进行心脏医学图像重建,重建表面的最大误差显著减少,重建精度较高,重建时间减少,在实时性和精确性上性能优越。 相似文献
3.
不规则单帧运动图像在目标成像与识别过程中会产生畸变和边缘动态失真,成像效果不好。提出一种基于RGB位平面分解的不规则单帧图像三维矫正技术,设计RGB位平面分解模型并对图像像素遍历机制进行改进,对单帧运动图像进行全局运动参数估计。把不规则的单帧运动图像纹理结构信息反映到灰度场空间中,得到图像全局运动空间单元三维姿态嵌入隐秘信息传导函数,实现对三维姿态矫正。实验结果表明,改进算法得到的姿态矫正偏移量比传统方法缩小,矫正精度较高,峰值信噪比提高,展示算法的优越性能,在运动图像融合和识别等领域具有很好的应用价值。 相似文献
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《科技通报》2016,(5)
提出了一种基于双目立体视觉的玉米叶片三维重建方法。该方法利用两个平行且位置相对固定的摄像机,组成双目立体视觉系统。运用改进的张正友平面标定法进行摄像机标定,采用一种改进的Harris算法,通过快速预筛选和多阈值角点提取方法,对获取的图像采集Harris角点以提取玉米叶片特征,通过计算搜索窗口内对应点的相关系数和阈值的比较实现特征点匹配,依据视差原理,计算得到玉米叶片的三维点云信息,对预处理后的玉米叶片点云进行双三次B样条曲线插值,重构叶片的三维网格曲面。仿真实验表明:所提方法能够高效、准确地实现玉米叶片三维重建,对玉米叶片边缘起伏和褶皱等细节可完整保留,三维重建精度较高。 相似文献
5.
随着计算机视觉以及图像处理技术的发展,视觉测量技术越来越受到人们的关注.建立物体相对姿态测量系统,使用两个相机在不同角度拍摄同一个物体上的编码标志点,采用张氏标定法对两个相机的空间位置关系进行标定;对摄像机采集到的图像进行去噪、滤波;左右两个相机采集下来的图像进行编码标志点的匹配,得到物体上粘贴的编码标志点的三维坐标,通四元数法计算物体间的相对空间姿态(欧拉角以及平移量);通过实验表明,该测量系统结构简单,计算量小,测量精度高. 相似文献
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三维测量系统应用广泛,对测量系统光源进行精确标定有利于提高三维测量系统的精度。本文通过对摄像机和所用高反射球标定,用T-S模型对近场点光源位置进行标定,用棋盘格标定主光轴,最后用得到的光源信息对平板灰度值图像进行模拟,通过与真实图像的对比验证结果准确性。 相似文献
8.
在一些连续帧的运动图像中,连续图像帧之间运动姿态点差异很小,形成像素粘连。这些细微的粘连差异特征不能形成很好的特征分离,将影响后期的处理精度。提出一种小差异运动图像中关键兴趣姿态点的差异特征分离方法,通过计算连续运动图像帧的轮廓像素空间位置参数,设置轮廓像素方向分量,计算任意像素两端的灰度值,通过运动图像窗口的移动,进行像素灰度累加,完成连续帧图像轮廓区域空间位置参数,结合连续图像间的差异拟合参数,破处粘连,实现小差异运动图像中关键兴趣姿态点的差异特征分离。仿真实验结果表明,该方法可以对高精度连续图像帧之间的运动特征差异进行分离,提高特征提取精度。 相似文献
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相机标定是三维重构中的关键步骤,本文对在自标定下的两视图三维几何模型恢复进行研究。先采用SURF算法得到图像匹配点对,在此基础上,利用RANSAC鲁棒估计基础矩阵;然后根据Kruppa方程所推导出的二次方程自标定出相机内参数,进一步地,通过分解本质矩阵求解出相机外参数;最后,根据三角化法求得空间三维坐标值。实验结果证实,该方法具有效性和正确性,并且能够真实地再现物体的三维模型。 相似文献
11.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
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
12.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US 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 the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
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
13.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
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
14.
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
15.
Puay Tang 《The Information Society》1998,14(1):19-31
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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Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
17.
Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
18.
《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献
19.
Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels 总被引：1，自引：0，他引：1
《中国科学院院刊(英文版)》2014,(3):267-268
<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese 相似文献
20.
WANG Sijia 《中国科学院院刊(英文版)》2014,(2):192-194
<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages. 相似文献