【作者】 王涛；

【导师】 孙长库；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2010， 博士

【摘要】 物体的三维形貌信息能够提供丰富的数据,在工业生产中得到了越来越广泛的应用,目前三维形貌的获取已不是技术难题,其发展趋势已经转向更高精度和更快速的测量。本文以三维形貌快速测量为研究的出发点设计了基于标记光栅和傅立叶轮廓变换三维形貌测量系统,该系统结构简单,容易标定,利于便携,测量时无需参考平面辅助,测量速度快,并具有较高的测量精度。研究成果在三维数据库的快速建立、产品在线检测、动画设计、虚拟现实等领域有着较为广泛的应用价值。论文主要研究内容如下:1.对傅立叶轮廓变换术中的关键问题进行了研究和分析,通过背景噪声去除,频域滤波等多种手段,提高傅立叶轮廓术的测量精度。2.研究了二维平面相位展开算法,并根据具体的测量情况进行了分析和改进。总结了各种算法的适应性,解相速度和解相效果。针对混合光栅编码的核心问题时间轴解相位算法进行了分析和讨论。3.提出了基于辅助参考线的系统测量模型。该方法摆脱了参考平面在测量中和标定中的束缚,使得系统的搭建、标定都具有很大灵活性和便携性。4.设计了圆线型靶标,给出了基准线的提取方法。利用自动阈值分割算法、噪声去除算法及椭圆中心提取算法,准确确定靶标点坐标信息的图像处理流程。进一步简化了标定过程。5.进行了测量系统精度验证和人脸测量实验,测量了一个220mm标准半球的直径,通过五次球直径的拟合,平均值为219.95mm,均方差为0.48mm,五次测量中,三维数据点同标准球面距离的均方差为0.28-0.46mm之间。6.设计了标记光栅,采用标记光栅法对一名实验人员面部表情进行了测量实验,仅用一幅带有特征矩形的变形光栅图即完成对人脸表情的三维动态采集,所获得的三维造型真实,数据信息丰富,获取速度快。7 .通过彩色相机颜色映射模型对被测人脸进行了色彩渲染,实现了彩色三维数据的动态测量。更多还原

【Abstract】 Three Dimensional morphology of objects can provide more plentiful data than 2D does , and it is needed more and more in industry .Currently, the acquirement of 3D data is not technical problems, the trend has shifted to higher speed and accurate measurement. In this paper, According to the purpose of get 3D morphology of the object in a fast way, a new measurement system is designed which is based on the grating patterns and Fourier transform profilometry(FTP).The system is convenient and simple in structure, and easy to be calibrated, it need not assistant by the reference plane when measurement and calibration is proceeding, high speed in capturing data and also with a good accuracy. This research will be widely used in rapid establishment of three-dimensional database, product online testing, animation, virtual reality and other fields.The main contents of this paper is as follows:1. Fourier transform profilometry is studied, including the theory of FTP, and the background noise reduction, frequency filtering and other means to improve the measurement accuracy of Fourier transform profilometry.2. Two-dimensional phase unwrapping algorithm is researched, according to the different measurement conditions, the adaptive method were supplied. The several different algorithm is compared, including their speed , the effort of the unwrap phase. And the unwrap method according to time direction is also discussed.3. A novel grating projection system based on assistant line and its calibration method is porposed .The equation of translation from relative phase to absolute phase is deduced according the assistant line. Space mapping method and its optimization algorithm is employed, by which the object’s real 3d data can be calculated.4. A circle liner target is designed, with which the extraction of feature points and feature line can be accomplished by one image. In the system calibration, Zhang’s camera calibration is adopted, the procedure of the calibration is simplified.5. The accuracy of the result is proved by measuring a standard hemispheroid with 220mm in diameter five times , the average of the fitting diameter is 219.95mm,and the mean square error is 0.48mm. and the mean square error of the distance between the 3D points and the spherical surface is arranged in 0.28-0.46 mm. The face with different expressions of a student is measured by the system , the 3D data is acquired by the system with only one fringe pattern and shows a vivid profile of the face.6. A binocular vision system which aims at the 3D texture mapping is designed. In this system, one gray camera captures the 3D coordinates, and one color camera acquires color information. The pixel matching model of binocular cameras was established, in which the intrinsic and structural parameters were defined using one simple calibration method.3D texture mapping model was created with the definition of the higher pixel matching model. The process of the proposed 3D texture mapping method was introduced in detail.更多还原