轮胎静特性试验台的标定

提出了轮胎静特性试验台的标定方法,导出了标定系数的计算表达式,给出了滑台转角调零的方法。     

基于角度不变的线阵推扫式CCD相机几何畸变在轨检校方法

对航天遥感相机进行在轨检校,是提高卫星产品质量,扩大产品应用效果的重要技术内容.文中研究了一种基于角度不变的线阵推扫式CCD相机几何畸变在轨检校方法.该方法利用相机外方元素对于相机视向量夹角角度影响比较小的原理,根据地面控制点和一级产品图像,求解相机视向量夹角,从中提取相机光学部件的畸变模型参数,从而实现相机内外方元素解耦.相机畸变模型采用一维3阶多项式,对焦距和主点等引起的低阶误差能够很好地吸收.该方法用在HJ-1A/B卫星的宽幅盖CCD相机几何畸变校正上,检校误差残留在2—6个像元,和参考数据精度相似,表明取得了很好的校正效果.     

Robust metric calibration of non-linear camera lens distortion

Camera lens distortion is crucial to obtain the best performance cameral model. Up to now, different techniques exist, which try to minimize the calibration error using different lens distortion models or computing them in different ways. Some compute lens distortion camera parameters in the camera calibration process together with the intrinsic and extrinsic ones. Others isolate the lens distortion calibration without using any template and basing the calibration on the deformation in the image of some features of the objects in the scene, like straight lines or circles. These lens distortion techniques which do not use any calibration template can be unstable if a complete camera lens distortion model is computed. They are named non-metric calibration or self-calibration methods.Traditionally a camera has been always best calibrated if metric calibration is done instead of self-calibration. This paper proposes a metric calibration technique which computes the camera lens distortion isolated from the camera calibration process under stable conditions, independently of the computed lens distortion model or the number of parameters. To make it easier to resolve, this metric technique uses the same calibration template that will be used afterwards for the calibration process. Therefore, the best performance of the camera lens distortion calibration process is achieved, which is transferred directly to the camera calibration process.     

Revisiting Zhang's 1D calibration algorithm

In recent years, the camera calibration using 1D patterns has been studied and improved by researchers all over the world. However, the progress in that area has been mainly in the sense of reducing the restrictions to the 1D pattern movement. On the other hand, the method's accuracy still demands improvements. In the present paper, the original technique proposed by Zhang is revisited and we demonstrate that the method's accuracy can be significantly improved, simply by analyzing and reformulating the problem. The numerical conditioning can be improved if a simple data normalization is performed. Furthermore, a non-linear solution based on the Partitioned Levenberg-Marquardt algorithm is proposed. That solution takes advantage of the problem's particular structure to reduce the computational complexity of the original method and to improve the accuracy. Tests using both synthetic and real images demonstrate that the calibration method using 1D patterns can be applied in practice, with accuracy comparable to other already traditional methods.     

测试／校准实验室如何建立管理体系

测试／校准实验室是为社会提供测试／校准有效数据的实体,为保证测试／校准结果的有效,军事测试／校准实验室应按照GJB2725A-2001《测试实验室和校准实验室通用要求》建立管理体系。依据GJB2725A-2001的要求,在管理体系建立上,通过组织准备、管理体系策划、文件编制、管理体系试运行、管理体系正式运行和保持等五个方面的分析,探讨了军事测试／校准实验室应如何建立和保持一个运行有效的管理体系的方法。     

半导体照明中结温的电学法测试与优化

基于电学法测试半导体照明的结温,实现了结温测试的电路,采用脉冲调制对LED的瞬态结温值进行测试.实脸发现,结温与正向电压的标定系数K值是影响结温测试精度的主要因素,分析了产生误差的主要原因,并对该系数进行修正.测试结果表明:结温的实测值与参考值有良好的一致性,存在误差的原因是采样的延时时间较长,可提高数据采样率和剔除不...     

Analysis and evaluation of a general camera model

A versatile General Camera Model, GCM, has been developed, and is described in detail. The model is general in the sense that it can capture both fisheye and conventional as well as catadioptric cameras in a unified framework. The camera model includes efficient handling of non-central cameras as well as compensations for decentring distortion. A novel way of analysing radial distortion functions of camera models leads to a straightforward improvement of conventional models with respect to generality, accuracy and simplicity. Different camera models are experimentally compared for two cameras with conventional and fisheye lenses, and the results show that the overall performance is favourable for the GCM.     

基于OpenCV的改进两步法摄像机标定

采用改进两步法实现了摄像机的标定,并给出基于OpenCV算法,充分发挥了OpenCV的函数库功能。对两步标定法的改进是在原两步法得到摄像机参数值的基础上,用非线性优化算法对所有参数进一步优化,得到最终参数值,既提高了摄像机标定精度和计算效率,又无需对摄像机像面中心预标定,简化了标定过程。     

一种获取Q60校色卡扫描颜色值的方法

对扫描仪进行颜色校正实验时,经常需要计算Q60校色卡被扫描后的颜色值,但校色卡的扫描颜色值不太容易获取,因为校色卡的每个色块经扫描后都包含数千个像素点,每个像素的颜色值各不相同。提出一种利用BMP图像文件属性,在VC＋＋环境下,直接编程计算Q60校色卡每一色块的扫描颜色值的方法。实验结果证明,该方法所测得的数据可靠,且简单易行,因此具有较高的实用价值。     

基于ROI的智能交通系统摄像机控制算法

针对城市道路监控的需求,提出了一种基于感兴趣区域的摄像机自适应控制方法。它作为车牌识别系统的一个辅助功能,在固定光圈的情况下,能够根据车牌识别和运动检测的反馈信息自适应地调节摄像机的快门和增益,获取较好质量的图片,从而达到提高车牌识别率的作用,特别是该方法能够大大降低强逆光和强眩光现象对采集图像质量的影响。