An image-based LCD positioning system utilizing the modified FHT method

In this paper, a LCD positioning system based on an image processing method is described. This method is effective in finding the angle of the geometric features in the cross registration mask. However, when two marks appear in the same frame, the problem of situation verification becomes more complex. We use an algorithm that assists with calculating the location and rotation angle for two marks precisely and quickly using the Fast Hough Transform (FHT). This method determines the locations of two masks and calculates the rotation angle from a blurred edge to adjust the LCD position and orientation.     

物像空间位姿表征模型及标定技术研究

从对单目视觉系统的空间定位技术着眼，本文研究了一种利用标准平面镜反射辅助三维空间测量的模型和方法。首先基于摄像机标定的基本原理，以条纹反射检测系统为初始结构，建立应用标准镜测量显示屏的空间位姿的物理模型，然后在对摄像机标定不确定度进行实验标定的基础上，进行了对条纹反射检测系统的三维空间位姿描述和测量。研究结果验证了本文技术方法模型有效、精度较高，扩大了单目视觉系统的测量范围，获得了更加紧凑的物像空间位姿测量系统结构。     

针对图像序列的快速低存储开销配准算法

针对序列图像配准问题，提出一种快速低存储开销配准算法。首先，生成一系列与具体图像内容无关的特征点。而后，使用正向-反向跟踪来获取稳定的特征点对,其中，正向跟踪用于获得所有可能的特征点对，反向跟踪用来得到正向-反向误差，并且利用此误差来获取最终稳定的特征点对。最后，在稳定特征点对的基础上通过归一化直接线性变换计算得到可用于图像配准的单应矩阵。实验表明该算法能够提供与优秀的传统算法相当的配准性能。由于该算法对序列中图像之间的连续性进行了充分利用，不仅降低了存储开销，还提高了运算速度。对480360的序列而言，该算法需要的存储开销仅为421 kB，且运算速度达到32 帧/s。     

Fast inversion of matrices arising in image processing

In recent years, new nonlinear partial differential equation (PDE) based approaches have become popular for solving image processing problems. Although the outcome of these methods is often very promising, their actual realization is in general computationally intensive. Therefore, accurate and efficient schemes are needed. The aim of this paper is twofold. First, we will show that the three dimensional alignment problem of a histological data set of the human brain may be phrased in terms of a nonlinear PDE. Second, we will devise a fast direct solution technique for the associated structured large systems of linear equations. In addition, the potential of the derived method is demonstrated on real-life data. This revised version was published online in June 2006 with corrections to the Cover Date.     

Super-resolution reconstruction face recognition based on multi-level FFD registration

Super-resolution (SR) reconstruction is an effective method to solve the problem, that the face image resolution is too low to be recognized in video, but the non-rigid change of deformed face and expression changes greatly affect the accuracy of registration and reconstruction. To solve these problems, a method of multi-level model free form deformation (FFD) elastic registration algorithm based on B spline is proposed. It first use low-resolution FFD grid for global registration, to emphasize the contribution of edge information for registration, we introduce edge registration measure into the sum of squared difference (SSD) criterion. Then divide the global registration image and reference image into a series of corresponding sub-image pairs and calculate the correlation coefficient of each pair; at the same time, we do local registration with high-resolution FFD grid to the small value correlation coefficient sub-image pairs. In the registration process of optimization, the paper uses adaptive step length gradient descent method algorithm based on chaotic variables to improve optimization efficiency. After registration, the algorithm of project onto convex sets (POCS) is used to reconstruct SR face image through several low resolution image sequences, and then recognized these SR face images by support vector machines (SVM) classifier. Experimental results from standard video database and self-built video database show that this method can register and reconstruct face image accurately in the condition of great face deformation and expression change, while the face recognition accuracy is also improved.     

基于特征点的对数极坐标变换图像配准算法

介绍了一种新的图像配准算法,可以很好地解决图像配准中的平移、旋转和缩放问题。算法的实现是首先使用SUSAN算子提取两幅图像的特征角点,剔除虚假的特征点(噪声点),然后使用改进对数极坐标变换和投影相关匹配算法实现特征点匹配;结合亚像素定位技术,可以进一步提高算法的精度。     

An improvement of image registration based on phase correlation

This paper is dedicated to studying the extended phase correlation method that applies to the sub-pixel evaluation of translational displacement between images. On the basis of experiments, this paper proposes an improved version of classical Hanning window, with involving parameters optimization in the process. We add a window function to the input images in the space domain and a weighting function to the spectrum in the frequency domain. The statistics and distribution of errors prove the applicability of the proposal. The experimental results of the proposed extended phase correlation algorithm show the registration accuracy of 1/100 pixel.     

基于SD的城市户籍改革中公共服务政策创新效应的动态仿真研究——以南昌市为例

在城乡户籍限制壁垒正逐步削弱的大背景下,实现城市常住人口公共服务均等化对于区域经济发展具有重要意义.应用系统动力学的逐树设撤关联数结构行为检验建模方法,建立仿真模型,通过设置户籍政策调控参数、公共教育支出参数、就业和社会保障支出参数及医疗卫生支出参数,分析不同情景下的政策实施效果,探讨城市户籍改革中公共服务创新政策效应.结果表明,提高公共服务支出水平,扩大居住证含金量,有利于提升户籍改革效果.     

基于邻域特征点提取和匹配的点云配准

为解决噪声干扰、数据丢失情况下迭代最近点算法的鲁棒性差、配准精度低等问题,提出一种基于邻域特征点提取和匹配的点云配准方法.首先定义一个由点的k邻域曲率、点与邻近点的法向量内积均值以及邻近点与邻域拟合平面的欧氏距离方差等三部分组成的邻域特征参数,结合在移动最小二乘表面构造的曲率特征参数对点云进行两次特征点提取;其次依据直方图特征定义三个匹配条件,并用双重约束获得正确的匹配点对;最后在配准阶段,采用双向构建k维树的迭代最近点算法实现精确配准.实验结果表明,该算法的配准精度较迭代最近点算法提高了90%以上,并且能够在噪声环境下有效地完成缺失点云的配准,在鲁棒性和精确配准方面有明显优势.     

基于磁共振成像的人脑图谱构建方法研究进展

基于磁共振成像的脑图谱构建对于脑与认知科学的研究非常重要，借助脑图谱，研究者可以精确地分析比较不同的脑影像数据，然而目前尚没有比较统一的标准脑图谱.本文针对基于磁共振成像的脑图谱构建方法进行概述，首先介绍了人脑图谱构建的发展进程，阐述脑图谱构建中需解决的技术问题及其局限性；然后着重描述了构建脑图谱的基本方法；最后论述了应用脑图谱进行精确定量分析的统计学方法，包括基于体素的形态学测量分析法和基于纤维束示踪的空间统计分析法，并较深入地比较了两种方法的差异和近期研究进展.通过分析目前研究现状，本文总结了脑图谱构建研究中的主要方法及不足，并就该领域未来的研究进展进行了展望.