【作者】 张家林；

【导师】 蒋大林；

【作者基本信息】 北京工业大学 ， 电路与系统， 2002， 硕士

【摘要】 如今，评价皮肤表面的光滑度越来越受到人们的重视，尤其是在化妆品研究领域。科学家们已经建立了几种检测皮肤皱纹、评价皮肤表面光滑度的方法。本文比较详细地介绍了各种皮肤皱纹检测的技术，并且对它们各自的优缺点以及适用范围进行了比较。另外，本文提出了基于立体视觉的皮肤表面检测技术，然后，分别对摄像机定标和立体匹配技术进行了研究。 在摄像机定标部分，本文介绍了摄像机定标的基本原理以及定标的具体步骤。在实验中，我们研究了定标点的密度极其分布对摄像机定标精度的影响。通过对实验结果进行分析，我们提出了用平面方格图对摄像机进行定标的方法。它使得定标点在空间分布更加均匀，定标精度提高。在计算定标点的图象坐标时，我们采用了哈夫变换的方法求出定标方格图上格线的方程，然后再求格线交点的图象坐标，从而使定标的参数更准确。 在立体匹配部分，我们着重介绍了区域匹配技术以及用于全局控制的极线约束方法。并且在实验的基础上，提出了一种基于标准点约束的全局控制策略。与极线约束的控制策略相比，它不受定标精度的影响，而且处理简便。 最后，总结全文。对自摄的图象进行了实验，并且分析了实验结果和系统的性能。指出今后需进一步研究和探索的方向。更多还原

【Abstract】 Estimation of skin smoothness is of ever-increasing interest especially in the field of cosmetic research nowadays. There are some established methods for assessing skin surface. The paper interprets some measurement methods of skin surface and analyses them in detail. Furthermore, a measurement method of skin surface structure based on the image stereo is introduced. In the following part, the main items of binocular stereo vision are presented systematically. At first, the development of binocular stereo vision and some viewpoints about computer vision are discussed. Then we discuss the techniques of the camera calibration and stereo matching respectively.In the camera calibration part, the basic principles and specific steps of camera calibration are presented. The effect of the density and distribution of the known calibrating points on the precise of the camera calibration is studied by experiments. By analyzing the results of the experiments, we propose a method of using a plane to calibrate a camera. It makes the distribution of the calibrating points more even in the space and the result of the camera calibration more accurate. In order to find the location of the cross points in the image, we first obtain the equations of the lines in the image plane by using Hough transform and then get the cross points of the lines. The result of the camera calibration using this method is more accurate.In the stereo matching part, the area-based stereo match and the control strategy based on epipolar line are discussed in detail. On the basis of experiment, we propose a new solution to stereo matching by using the control strategy of the standard points. In contrast to the control strategy based on epipolar line, it is free from the effect ofthe camera calibration.Finally, we review the whole work, process the images, analyze the results and suggest the direction for the future research in this field.更多还原