脊柱三维运动定位的计算机视觉方法

脊柱三维运动分析是利用计算机立体视觉方法 ,通过采用两台摄像机从两个不同视角观察脊柱。求取脊柱的三维坐标 ,采用计算机图像处理技术和立体测量术。精确地刻划脊柱的三维运动 ,系统地分析脊柱各部分结构对脊柱运动的影响 ,为脊柱矫形术和固定器械的应用提供稳定性评价 ,也可为临床提供一种精确测量脊柱三维运动的方法。文中主要从摄像机定标及如何求取脊柱上各点的三维坐标方面阐述 ,结果成功地建立了脊柱三维运动分析系统 ,并能在该系统上成功地进行脊柱运动的各项实验。     

基于正交平面的摄像机自定标

提出了一种基于正交平面摄像机定标的新算法。它利用场景中的正交平面,摄像机作五次以上的平移运动,根据每次运动关于平面的单应矩阵建立内参数的线性约束方程组,从而线性地确定内参数。与以往的定标方法相比,文章对摄像机的运动不苛刻,只需控制摄像机作平移运动,这在一般的实验平台上可以很容易地实现,并且线性地确定摄像机所有的五个内参数。模拟实验和真实图象实验表明,文章给出的方法在机器人视觉中具有一定的实用价值。     

一种新的摄像机自定标的方法

本文给出一种由未定标图像进行摄像机自定标的方法．通过分析基础矩阵关系式及方 差之间关系,得出一种新的计算摄像机内部参数及运动参数的准则．在计算中采用单个摄 像机并且假设摄像机像主点的位置已知,大大简化了运算量．     

运动图像序列的人体三维运动骨架重建

在计算机视觉领域 ,人体运动分析的研究具有相当广泛的应用前景 .由于人体运动的复杂性 ,已有的研究方法都对研究对象——人体 ,加上了许多限制条件 .文中提出了一种新的方法来获得各类人体运动的信息 .文中主要论述了该方法中对人体三维运动骨架的重建部分 ,其基本思想是在摄像机定标的基础上 ,应用三维人体模型知识和运动连续性依次建立每个图像的人体运动骨架 .最后给出了实验结果     

一种基于主动视觉的摄像机内参数自定标方法

摄像机定标是计算机视觉的一项基本任务．本文提出了一种基于主动视觉的摄像机内参数自定标方法．该方法和文献［1］提出的方法相比最大的优点在于不要求摄像机在三维空间作任意方向的平移运动，只需要控制摄像机在同一平面作四组运动，其中每组包括两次相互正交的平移运动，同时适当调整摄像机平移运动的姿态，可以线性求解摄像机内参数．理论上证明了如果摄像机作三次俯仰或者作两次俯仰一次扫视来调整摄像机平移运动的姿态，则解存在而且唯一．通过稳定性分析证明前一种方法对误差很敏感，后者则是稳定的．最后给出了采用真实图像的实验结果．     

基于限定的规划识别问题求解

该文把McCarthy的限定理论同规划识别结合起来，在限定中研究规划识别问题，证明了在一定的限制下，由观察到的现象求出的最小规划集与对这些现象作限定获得的解集是一样的，以此为基础，文中提出了一种用限定求解规划识别问题的方式，这种方法把Kautz提出的规划识别表示形式做了某些改变，求解的过程中把二阶限定的表示形式转化为一阶形式，这种一阶形式的限定结果可以用逐点限定的方法直接求得，因为利用了逐点限定的这一特点，该文的方法对限定的计算过程中可以用机器自动完成。     

摄像机沿光轴运动下的场景三维重建

讨论了采用针孔摄像机进行摄像机沿光轴运动下的场景三维重建的方法．基于摄像机轴向运动的特点和性质,利用该方法找到图像间的缩放因子,进而解决了轴向运动下的特征匹配;采用Sturm的摄像机自标定方法得到摄像机的内外参数;从而实现了摄像机沿光轴运动下的场景三维重建．     

基于运动矢量的摄像机运动定性分类方法

在视频序列中,摄像机运动在某种程序上反映了当前视频的语分语义信息,知道了摄像机运动将能够取更好的实现对视频的游览以及检索,针对现有的依据光流分布来摄像机运动参数算法中的不足,给出了一种定性分析相机运动的方法,该方法能够在相机聚焦中心－ＦＯＥ（focus-of-expansion)不在成像平面中心时检测出给定类型的摄像机运动,实验结果表明该方法对于从视频序列中分析出给定类型的摄像机运动具有较的效果。     

DLT模型在结构光测量方法中的应用

在计算机视觉领域,随着对测量精度的要求越来越高,摄像机定标技术非常重要.通过对DLT模型分析,提出一种新的定标技术,解决三维激光彩色信息获取系统中从单摄像机到双摄像机的结构光快速定标问题.     

基于主动视觉系统的摄像机自定标方法研究

提出了一种新的基于主动视觉系统的摄像机自定标方法,其主要特点是可以线性求解 摄像机的所有5个内参数.该方法的基本原理是利用图像中平面场景的信息,通过控制摄像机 作多组平面正交平移运动,由平面场景图像的单应性(homography)矩阵建立摄像机内参数线性 约束方程组,来求解摄像机的内参数,同时给出约束方程组解的唯一性与平移运动组之间的关系.     

直线运动摄像机在线动态标定

为实现AS-R智能机器人在运动情况下摄像机在线动态标定,提出一种新的基于粒子滤波的直线运动摄像机标定方法。用状态空间方法描述直线运动摄像机模型,把摄像机内参数和位置运动参数作为状态量,特征点图像坐标作为观测量,根据粒子滤波算法求得摄像机内参数和位置运动参数的最优估计,并用双线程实现整个标定过程。AS-R机器人在直线运动情况下的摄像机在线动态标定实验结果表明：该算法是合理可行的,并且具有很高的标定精度和良好的鲁棒性。该方法适用于各种类型的系统噪声。     

The Research of Movement Simulation in Bianzhong Choreography

This paper introduces the process of producing movement database on a virtual model for the Bianzhong choreography. It focuses on analyzing the movement taxonomy and corresponding relationship under the dancing syntax. We study the movement style identification theory based on the emotion model, present a movement connection method by defining the attributes of characteristically movement units and their related restriction, and give the application framework of the method in Movement Compilation System.     

基于LSTM的眼动行为识别及人机交互应用

眼动交互在人机交互领域中有着广泛的应用前景,针对传统的眼动交互传感设备具有普遍侵入性,校准过程复杂且价格昂贵,普通单目摄像头传感器分辨率低等问题.提出一种基于前置摄像头视频源,使用方向梯度直方图（HOG）特征+SVM+LSTM神经网络的眼动行为识别方法,进而实现了简单的人机交互应用.该方法首先定位和跟踪人脸,在人脸对齐操作后依据4个眼角关键点的坐标获取双眼区域,使用SVM模型判断眼睛的睁闭眼及非眨眼状态,再分析相邻帧之间眼球中心的位置粗略判断眼动情况,将可疑的有意眼势帧间差分视频序列输入到LSTM网络中进行预测,输出眼动行为识别结果,进而触发计算机命令完成交互.经过自制数据样本集20 000个样本（其中约10%为负样本）测试,本文方法动态眨眼识别准确率优于95%,眼动行为预测准确率为99.3%.     

基于手眼标定方程AX=XB的精度影响因素研究

机器人手位姿数据对手眼标定精度的影响不可忽略,将对基于手眼标定方程AX=XB的精度影响因素进行分析.通过手眼标定仿真和实测实验验证上述两个因素对手眼标定精度的影响与理论分析的一致性.通过仿真与实测实验,总结得出了减小摄像机与靶标间距离、减小机器人手的运动前后到基坐标空间距离的相差距离,可提高手眼标定精度,通过四元数法和矩阵直积法验证了此规律在解AX=XB标定方程时的通用性,并且在摄像机与靶标间距约为230 mm以及机器人手的运动前后到基坐标空间距离的相差距离为3.2401 mm时,手眼标定平移向量相对误差最高精度可达0.0403%.     

基于图像传感器的脉搏三维运动分析

采用一种自主研制的图像化脉搏传感器,采集脉搏动态图像。在单个CCD摄像头固定的情况下,建立投影几何模型,计算所获取的动态图像上特征点的空间位移,得到时域上连续的脉搏信号。结果表明该方法能较好地反映出脉搏波动及传播特性,有利于脉搏传播分析和脉诊客观化的研究。     

A new robust algorithmic for multi-camera calibration with a 1D object under general motions without prior knowledge of any camera intrinsic parameter

In computer vision, camera calibration is a necessary process when the retrieval of information such as angles and distances is required. This paper addresses the multi-camera calibration problem with a single dimension calibration pattern under general motions. Currently, the known algorithms for solving this problem are based on the estimation of vanishing points. However, this estimate is very susceptible to noise, making the methods unsuitable for practical applications. Instead, this paper presents a new calibration algorithm, where the cameras are divided into binocular sets. The fundamental matrix of each binocular set is then estimated, allowing to perform a projective calibration of each camera. Then, the calibration is updated for the Euclidean space, ending the process. The calibration is possible without imposing any restrictions on the movement of the pattern and without any prior information about the cameras or motion. Experiments on synthetic and real images validate the new method and show that its accuracy makes it suitable also for practical applications.     

Self-identifying patterns for plane-based camera calibration

Determining camera calibration parameters is a time-consuming task despite the availability of calibration algorithms and software. A set of correspondences between points on the calibration target and the camera image(s) must be found, usually a manual or manually guided process. Most calibration tools assume that the correspondences are already found. We present a system which allows a camera to be calibrated merely by passing it in front of a panel of self-identifying patterns. This calibration scheme uses an array of fiducial markers which are detected with a high degree of confidence, each detected marker provides one or four correspondence points. Experiments were performed calibrating several cameras in a short period of time with no manual intervention. This marker-based calibration system was compared to one using the OpenCV chessboard grid finder which also finds correspondences automatically. We show how our new marker-based system more robustly finds the calibration pattern and how it provides more accurate intrinsic camera parameters.     

The Effect of Noise on Camera Calibration Parameters

Camera calibration is the estimation of parameters (both intrinsic and extrinsic) associated with a camera being used for imaging. Given the world coordinates of a number of precisely placed points in a 3D space, camera calibration requires the measurement of the 2D projection of those scene points on the image plane. While the coordinates of the points in space can be known precisely, the image coordinates that are determined from the digital image are often inaccurate and hence noisy. In this paper, we look at the statistics of the behavior of the camera calibration parameters, which are important for stereo matching, when the image plane measurements are corrupted by noise. We derive analytically the behavior of the camera calibration matrix under noisy conditions and further show that the elements of the camera calibration matrix have a Gaussian distribution if the noise introduced into the measurement system is Gaussian. Under certain approximations we derive relationships between the camera calibration parameters and the noisy camera calibration matrix and compare it with Monte Carlo simulations.     

Autonomous robot calibration using vision technology

Unlike the traditional robot calibration methods, which need external expensive calibration apparatus and elaborate setups to measure the 3D feature points in the reference frame, a vision-based self-calibration method for a serial robot manipulator, which only requires a ground-truth scale in the reference frame, is proposed in this paper. The proposed algorithm assumes that the camera is rigidly attached to the robot end-effector, which makes it possible to obtain the pose of the manipulator with the pose of the camera. By designing a manipulator movement trajectory, the camera poses can be estimated up to a scale factor at each configuration with the factorization method, where a nonlinear least-square algorithm is applied to improve its robustness. An efficient approach is proposed to estimate this scale factor. The great advantage of this self-calibration method is that only image sequences of a calibration object and a ground-truth length are needed, which makes the robot calibration procedure more autonomous in a dynamic manufacturing environment. Simulations and experimental studies on a PUMA 560 robot reveal the convenience and effectiveness of the proposed robot self-calibration approach.