结构光双目测量系统标定方法

为了解决双目结构光测量系统参数不容易准确获取的问题,依据传统摄像机标定方法,结合结构光双目测量系统的特点,提出了CCD摄像机标定方法.通过对左右CCD摄像机采集得到的两幅标定模块的图像数据分析,按照"两步"标定法的思路,先得到平移向量R和旋转矩阵R等外部参数,再利用已知的空间距离求解到摄像机的成像模型需要标定的其他参数.实验数据表明,该方法可简便、准确地标定出CCD摄像机参数,方便了三维视觉测量工作,是一种有实用性的标定方法.     

CCD摄像机镜头薄棱镜畸变的研究

本文以CCD摄像机小孔成像模型为基础建立了薄棱镜畸变的非线性几何畸变模型,通过对影响畸变参数测量精度的各种因素的分析,使用最小二乘法解线性方程组得到摄像机系统畸变模型的畸变系数。通过与径向畸变相对比得出薄棱镜畸变对摄像机标定的影响相对较小,在此基础上提出了提高标定精度的有效方案。     

GRB-400机器人摄像机内外参数的分离标定

以GRB-400四自由度工业机器人为研究对象,利用一种介于传统标定方法和自标定方法之间的内外参数分离的标定方法,对机器人的CCD摄像机进行了标定,获得了较精确的摄像机内、外参数。该方法的特点是比传统标定方法简单快速,同时克服了自标定方法精度不高的缺点。     

数字图像测温系统温度标定过程中的误差分析

在利用CCD摄像机所摄彩色图像进行温度测量的技术中,需要对CCD摄像机进行温度标定,从而运用相关技术对相关环境下的温度进行测量.在标定过程中,由于设备、环境等因素的不同及其这些因素自身的变化,都会影响温度标定,产生误差.对这些误差产生的原因进行分析,提出相关的减小误差的方法,能使得温度标定有一个稳定的结果.     

数字图像测温系统温度标定过程中的误差分析

在利用CCD摄像机所摄彩色图像进行温度测量的技术中，需要对CCD摄像机进行温度标定，从而运用相关技术对相关环境下的温度进行测量。在标定过程中，由于设备、环境等因素的不同及其这些因素自身的变化，都会影响温度标定，产生误差。对这些误差产生的原因进行分析，提出相关的减小误差的方法，能使得温度标定有一个稳定的结果。     

基于Matlab的双目CCD标定

CCD标定作为图像采集处理的前端,直接影响到后继信息的处理.用Matlab软件实现CCD摄像机内外参数的标定,得出旋转矩阵和平移向量,并验证镜头畸变量对数据的影响.通过双目CCD交互式测距验证,测量结果误差小于0.3 mm,满足工业要求.     

一种摄像机标定系统的实现

摄像机标定系统中的参数直接影响摄像机三维重建效果的逼真度。本文以张正友两步标定法为基础,设计制作标定模板,并采用针孔摄像机模型对摄像机标定参数的求解过程进行了优化;结合OpenCV库,在Matlab开发环境下实现了摄像机标定系统。实验结果表明,该方法提高了摄像机的标定精度。     

基于Matlab的摄像机标定方法研究

摄像机标定的目的是建立三维坐标与二维图像坐标之间的对应关系,由摄像机拍摄的二维图像通过计算和实验得到物体的三维坐标值.基于摄像机的针孔模型,阐述了摄像机的标定原理和引起摄像机畸变的原因,在Windows系统下利用Matlab的摄像机标定工具箱进行了平面标定模板的角点提取和校正并给出了标定摄像机的参数表.实验表明,该标定方法和标定过程标定精度高、易于实现.     

高速CCD像机的测温系统标定方法

基于CCD测温方法是一种非接触式的高温测温方法,一般工业用CCD摄像机测温范围较窄,无法满足现代高温测量中对测量带宽的要求,使用超高速CCD摄像机进行温度测量可以克服一般CCD相机单幅图像量程不足的缺点。根据比色测温原理,设计了温度标定实验,并提出了针对不同快门速度下,建立了温度与比色值的数学模型。超高速CCD相机测温数据与实际温度数据之间存在良好的对应关系,单幅图像数据测温范围在500K左右,该系统具有实际的应用价值。     

高速CCD视频摄像机的设计与研究

针对大视场、高帧频、多目标电视测量系统,介绍了高速CCD视频摄像机的设计和研究。研究高速CCD视频信号的产生,给出相应的电路设计。建立并分析了信号变换模型。基于设计的信号变换电路,可把高速CCD视频摄像机和标准TV监视器、录像机联合起来使用,实现高速CCD视频信号的显示与记录,而不需要昂贵的辅助仪器。实验结果表明高速CCD视频摄像机的适用性。     

基于图像反馈的标靶面与光轴垂直调节系统

介绍了摄像机标定的内部参数,阐述了标靶面与光轴垂直可以简化标定的过程.当标靶面与光轴垂直时,利用标靶面上特征圆在CCD成像面上成像也是圆的特点,提出了基于图像反馈的标靶面与光轴垂直的调节方法.一般情况下,标靶面与光轴不垂直,标靶面上特征圆在CCD成像面上成像为椭圆.通过图像处理和最小二乘椭圆拟合法计算出成像椭圆的长短轴及偏角,设计了调整控制策略.实验结果表明,该方法是有效可行的.     

基于径向约束的CCD相机标定参数的整体优化

提出了基于径向约束的CCD相机标定的模型参数非线性整体优化的方法.利用Harris算法检测标定板的各角点图像坐标,保证了标定板角点的稳定性和可靠性;进行RAC(radial alignment constraint)两步法标定,并用Levenberg-Marquardt算法对通过径向约束标定得到的所有相机模型参数进行非线性整体优化,提高了相机参数的标定精度.实验结果表明.该方法标定精度高,能明显减小各种误差对CCD相机标定的影响,提高了机器视觉三维测量的精度.     

双线阵CCD交汇测量中的自动标定方法

针对CCD交汇测量系统中的初始标定困难、繁琐、重复误差等缺陷,提出了一种基于测量模型的自动标定方法.根据交汇测量原理,建立了测量系统的数学模型,并推导出自标定的模型.在相机焦距、倾角、光心坐标已知条件下,通过分析标定中各参量的函数关系,可利用线阵相机像元确定测量位置,精度可达到4 mm.     

机器视觉中彩色伪随机编码投影系统及标定

为了研究基于三维场景单幅二维图像的不标定欧式重构理论,需要构造一个编码投影系统,并预标定出其相关参数,依据伪随机彩色编码的原理,代数射影几何中的交比不变性质,以及被视为逆向照相机投影系统的标定数学模型,提出了投影系统的标定步骤和方法．将一幅伪随机编码图案与投影系统相结合,构造了一种新的视觉投影系统．标定实验表明,由此系统将伪随机彩色编码图案投射到靶标空间,利用CCD照相机拍摄其图像,进行图像的特征点提取和数据处理后得到了投影系统的参数。     

Study on the relative radiometric correction of CBERS satellite CCD image

China-Brazial Earth Resources Satellite (CBERS)-01 is the first remote sensing re- source satellite of data transfer type manufactured by China and Brazil, which is full of the wisdom and sweat from both countries’ aerospace communities and is regarded as a model of the cooperation between developing countries in high-tech area. CBERS-01 was launched in October of 1999 and went into normal operation after on-orbit test inMarch of 2000. This brought an end to the history that China coul…     

Study on the relative radiometric correction of CBERS satellite CCD image

The main payload on CBERS-01/02 of China-Brazil Earth Resources Satellite (CBERS) is a push-broom CCD camera with moderate spatial and radiant resolution. Because at lab the data for calibration at satellite assembly stage were unable to be collected, and also because the onboard calibrator after launch was in a different state from imaging, the calibration of CCD image got a series of difficulties involved. In practice, two methods are used in the processing on the ground station: One is extracting calibration data by statistics from the image itself, and the other is the method of histogram match. It was proved that the latter can calibrate the image much better, because it can remove the effect of unstable response of the camera largely and also can overcome the nonlinearity of the camera basically by using Look-Up Table (LUT) calculated from histogram statistics of different temporal images. Considering the problems of CBERS-01, a lot of calibration tests were done before the launch of CBERS-02, in which a set of lab coefficients for relative calibration was formulated after the data collection by using integration-hemisphere in the stage of satellite assembly test. During the on-orbit test, it was found that the calibration result from such coefficients was not satisfying, especially there being response difference between 3 detector arrays, which was attributed to the unstable dark currents of the CCD camera. This paper comes up with a statistic method to remove such response difference. In this method the middle detector array was used as reference to find the response differences of adjacent similar features between these arrays and it was proved to have a broad adaptability.     

Water target based cross-calibration of CBERS-02 CCD camera with MODIS data

In order to make quantitative watercolor sensing with China-Brazil Earth Resources Satellite (CBERS-02) CCD camera, the MODIS data with higher accuracy is used to cross-calibrate the CCD camera over water targets. In homogeneous clear water area, two pairs of images obtained over the same area on the same day by the two sensors are selected. The top-of-atmosphere (TOA) radiances of the multispectral bands of CCD are calculated with the water and aerosol parameters from MODIS based on a water-atmosphere radiative transfer algorithm. The stripes in CCD image that caused by unequal response of the CCD array detectors are firstly removed before making the cross-calibration. The same part of CCD detectors is selected for the calibrations in the two images to eliminate the residual error of destriping and uniformity correction for the focus plane irradiance. It is shown that the calibration results from two different images are consistent. The error of this method is about 5%.     

Water target based cross-calibration of CBERS-02 CCD camera with MODIS data

The CBERS-02, the second satellite of China Brazil Earth Resources Satellite series, was launched on Oct. 21, 2002. Onboard the satellite, there are three major sensors, a CCD camera, a wide field imager and an infrared multispectral scanner (http://www. cresda.com). The purpose of this paper is to calibrate the CCD camera with a methodol- ogy of cross-calibration. The spatial resolution of the multispectal bands of CCD camera is 19.5 m, the swath is about 115 km. It is capable of side…     

基于CCD的轴径检测方法

给出了一种CCD相机标定与亚像素边缘检测相结合的轴径测量方法。该方法在修改了张正友标定方法中的畸变模型的基础上,利用专门设计的夹具夹持标定板进行CCD相机的外部参数标定,有效地保证了被测轴的夹持状态与标定的外部参数一致。使用拟合形式的亚像素边缘检测算法确定轴的两条边缘的位置,同时给出了利用伪直径确定真实轴径的函数关系式。通过与精密量具的测量结果对比,当轴径的基准尺寸在35～75mm时,该方法测量的平均误差为0.02mm。