基于改进SIFT算法的超声图像配准研究

针对SIFT算法对医学超声图像提取关键点数目较少的缺点,本文提出了采用HARRIS角点改进SIFT算法的方法,有效提取更具有结构意义的关键点数目,提高超声图像配准精度。此外,为进一步提高配准精度,增加一步互信息算法对图像进行精配。实验结果表明,本文算法是一种快速、高精度、全自动的医学图像配准算法,并可有效地提高配准精度。     

基于.NET技术的高校网上选课系统设计与开发

本文以我校教务网络选课系统的设计为例,根据学分制管理模式的特点,介绍了基于．NET技术的在线选课系统的开发,本系统采用B/S结构,基于MVC的.NET框架,包括网上选课系统的基本功能,优化教学资源,提高学生选课的质量,改善了我校教务管理环境,提高了我校的信息化管理水平。     

一种用于图像超分辨的实时高精度像素内配准方法

在超分辨图像复原处理中,像素内的配准精度、速度是超分辨图像最终实现的实时性和高质量的关键因素。传统的利用泰勒级数展开像素内配准方法实时性较差;分级少的块匹配配准精度相对较低。该文提出一种基于分段双三次多项式拟合的分级块匹配像素内配准技术,在算法复杂度低的同时保证了配准精度,并在文中给出了实验统计结果。     

图像平滑在地面激光点云与影像融合中的应用

针对地面激光点云与影像数据的融合,提出一种利用激光点云反射强度值将点云三维数据化为二维图像信息,根据图像的情况从多种图像平滑的方法中利用图像客观质量评价选择出一种最优的图像平滑的方法将激光反射强度图像进行去噪,最后利用激光反射强度图像与影像的匹配得到同名点,从而实现激光点云数据与影像数据的配准达到数据的融合。     

涡轮叶片形状检测中的模型配准控制点集选取

叶片模型的配准定位是叶片形状检测与分析的一个核心环节。为解决基于迭代最近点方法的叶片密集测量数据与其CAD模型的可靠配准问题,提出一种基于CAD模型的配准控制点集选取方法。结合模型配准可靠性分析技术,预先在叶片CAD模型规划出配准基准点集;通过测量数据与配准基准点集的配准运算,把配准基准点集映射到叶片测量数据上,获取测量模型上对应的配准控制点集;滤除其中可能降低模型配准精度的坏点,得到最终的叶片模型配准控制点集。进行基于仿真与实测数据的叶片模型配准试验及对比分析,总结出一些可用于指导叶片模型配准控制点集选取的策略。结果表明,所提出的叶片模型配准控制点集选取方法是可行的。     

Augmenting reality by using uncalibrated optical tracking

The paper describes the use of an optical tracking method for superimposing computer-generated images oriented and positioned in 3D to augment a real scene. In a medical scenario, a physician may view the images created by an ultrasound device directly related to the patient. Typically, the position of the images or the position of the physician changes almost always and the mapping of images has to be recalculated. The optical tracking method in combination with artificial landmarks, is used to get the information about how to transform the superimposed images After segmenting and tracking the landmarks the perspective transformation of the ultrasonic image can be determined.     

Adaptive and self-evaluating registration method for myocardial perfusion assessment

With the advent of ultra-fast MR I, it is now possible to assess non-invasively regional myocardial perfusion with multislice coverage and sub-second temporal resolution. First-pass contrast enhanced studies are acquired with ECG-triggering and breath holding. Nevertheless, some respiratory induced movements still remain. Myocardial perfusion can be assessed locally byparametric imaging methods such as Factor Analysis of Medical Image Sequences (FAMIS), provided that residual motion can be corrected. An a posteriori registration method implemented in the image domain is proposed. It is based on an adaptive registration model of the heart combining three elementary shapes (left ventricle, right ventricle and pericardium). The registration procedure is performed on a potential map derived from the distance map. To evaluate the quality of the registration procedure a superimposition score between the registration model and the contour automatically extracted in the sequence is proposed. Rigid transformation hypotheses and registration analysis provide an efficient and automatic method which allows the rejection of outlier images, such as; outof synchronisation images, out of plane acquisitions. When compared to a manual registration method, this approach reduces processing time and requires a minimal intervention from the operator. The proposed method performs registration with a subpixel accuracy. It has been successfully applied to simulated images and clinical data. It should facilitate the use of MR first-pass perfusion studies in clinical practice.     

Architects as Hairdressers

Neil Spiller reactionary? Spiller finds himself recoiling into a ‘grumpy old man’ as he observes the emergence of an alarming new trend in architecture schools that prioritises style over matter. Copyright © 2008 John Wiley & Sons, Ltd.     

尽快熟悉REACH积极应对REACH

扼要介绍了REACH的内容与特点,以及对中国化工出口的影响与对策。     

几种经典相似性度量的比较研究

以图像匹配概率和匹配精度为准则,对几种经典的相似性度量进行了比较研究。得出绝对差(AD)与平均绝对差(MAD)算法等价;平方差(SD)、平均平方差(MSD)、积相关(Prod)与归一化积相关(Nprod)算法等价的结论。当图像信噪比较低时,Prod/Nprod/SD/MSD算法优于AD/MAD算法;否则,后者优于前者。相似性度量的比较研究可为实际应用中图像配准或景象匹配问题中相似性度量的选择提供重要的参考依据。