3D靶标的摄像机三步标定算法与实现

摄像机标定是计算机视觉中的一个必不可少的重要环节,其标定精度影响着三维重建结果的精度。利用摄像机对一个三维正交的棋盘格拍摄一幅有效靶标图像,提取角点,第一步通过透视变换矩阵算法线性求解各内外参数;第二步引入径向和切向畸变,将第一步求得的内外参数作为初始值,求得畸变系数的解;第三步对内参数进行线性优化,得到更为精确的内参数值;最后求解反投影后图像坐标的绝对误差。实验结果表明,该方法具有较高的精度,且简单有效。     

The Visual Computing of Projector‐Camera Systems

This article focuses on real‐time image correction techniques that enable projector‐camera systems to display images onto screens that are not optimized for projections, such as geometrically complex, coloured and textured surfaces. It reviews hardware‐accelerated methods like pixel‐precise geometric warping, radiometric compensation, multi‐focal projection and the correction of general light modulation effects. Online and offline calibration as well as invisible coding methods are explained. Novel attempts in super‐resolution, high‐dynamic range and high‐speed projection are discussed. These techniques open a variety of new applications for projection displays. Some of them will also be presented in this report.     

Camera Control in Computer Graphics

Recent progress in modelling, animation and rendering means that rich, high fidelity virtual worlds are found in many interactive graphics applications. However, the viewer's experience of a 3D world is dependent on the nature of the virtual cinematography, in particular, the camera position, orientation and motion in relation to the elements of the scene and the action. Camera control encompasses viewpoint computation, motion planning and editing. We present a range of computer graphics applications and draw on insights from cinematographic practice in identifying their different requirements with regard to camera control. The nature of the camera control problem varies depending on these requirements, which range from augmented manual control (semi‐automatic) in interactive applications, to fully automated approaches. We review the full range of solution techniques from constraint‐based to optimization‐based approaches, and conclude with an examination of occlusion management and expressiveness in the context of declarative approaches to camera control.     

Repair approach for DMC images based on hierarchical location using edge curve

The color composite digital mapping camera (DMC) images are produced by the post-processing software of Z/I imaging. But the failure of radiometric correction in post-processing leads to residual radiometric differences between CCD images, which then affect the quality of the images in further applications. This paper, via analyzing the characters and causes of such a phenomenon, proposes a repair approach based on hierarchical location using edge curve. The approach employs a hierarchical strategy to locate the transition area and seam-line automatically and then repair the image through the global reconstruction between CCD images and the local reconstruction in the transition area. Experiments indicate that the approach proposed by this paper is feasible and can improve the quality of images effectively. Supported by the National Basic Research Program of China (Grant No. 2006CB701302) and the Youth Fundation Plan of Wuhan (Grant No. 200750731253)     

一种用于单摄像机视觉传感技术的新模型

提出了一种用于单摄像机视觉传感测量技术的新模型,该模型采用参数法可直接求解视觉传感测量过程中控制点的三维坐标,进而求出被测点的三维坐标.文中简要介绍了利用单摄像机测量目标三维坐标的工作原理与系统结构,给出了求解新模型的详细计算过程,并通过大量的实验来验证了新模型的正确性与有效性.     

基于三次B样条曲线的特色照相系统算法模型

给出了一套娱乐性照相系统的算法模型,其原型为哈哈镜.模型以三次B样条曲线为基础,主要为内存和计算能力有限的手机、PDA等手持设备设计.模型的基本思想是将图像抽象成一组直线的集合,将图像的变化看作是这组直线的变化;对这组直线的变化建立数学模型,使图像的变化变成可以描述并且可控制的数学表达式;再将这个教学表达式映射成图像的变化.为了增加模型的实用性,最后又对这个模型进行了优化,将图像的变化转变成图像像素坐标的变化,以变化模板的方式替代了复杂的计算,从而使模型更具有实际使用价值.     

基于某微型飞行器的2种图像导航算法性能比较

导航系统是微型飞行器中必不可少的重要部分,在城市、建筑物内部或强电磁干扰等环境下,要实现导航必须采用全新的技术。图像导航是其有效技术之一。根据微型飞行器导航系统实时性和算法精准性的要求,研究了2种图像导航算法：互相关匹配法和局部熵差法。为了降低计算量,使其易于工程实现,采用了分层搜索等技术,并对2种算法进行了改进。仿真结果表明：“互相关匹配法”更适合微型飞行器的图像导航。     

机载火控系统通用测试平台设计与实现

机载火控系统种类繁多,设备日益复杂且不断更新,对机载火控系统检测系统的开发速度和更新速度提出了更高的要求,通用测试平台能够实现测试设备的快速开发和同步更新,满足机务部队快速保障的需求;介绍了基于虚拟仪器技术和PC104总线的硬件通用平台的设计方法和基于测试模型的软件通用平台的设计方法;实践证明,该机载火控系统通用测试平台能够实现测试系统的快速开发和更新,且环境适应能力强,运行可靠,使用方便。     

双目定位在数码相机图像标定中的应用

数码相机定位是计算机图形学中的一个重要课题,在图像处理等方面有着广泛的应用,对数码相机进行合理建模分析,并利用双目视觉原理对图像进行标定,最后例证了此方法的有效性和精确性。     

面向3DTV的高分辨率摄像机阵列设计与实现

当前摄像机阵列采集的视频分辨率与帧率普遍不高,还不能满足制作高质量3DTV节目的需要。设计与实现了一种高分辨率摄像机阵列,可以依据应用需要,自由配置为27fps帧率1280×1024分辨率,或93fps帧率640×480分辨率两种模式。讨论了该摄像机阵列的总体结构设计、摄像机单元设计、同步控制机制与实时存储技术等。