三光带激光三维人体面部扫描系统的研制

论文编号:WLX004 论文字数:26118,页数:71

摘 要

本文在全面了解三维人体面部扫描技术国内外研究现状的基础上，基于激光三角法原理，根据分辨率高扫描时间短的要求，提出了三光带激光人体面部扫描方案，设计了系统的软硬件结构，对关键技术进行了研究，并成功研制出系统样机，进行扫描实验得到了预期的实验结果，验证了所设计系统的正确性。主要工作包括以下几个方面：

根据实际使用要求，提出了三光带激光人体面部扫描方案，用三个相同的线激光器产生三条平行且高度方向等间距的光带，扫描时每条光带只需移动整个扫描范围的1/3，满足了缩短系统扫描时间的要求。

设计了扫描系统的总体结构，包括传感器、运动系统、图像采集系统和计算机处理系统，编写了控制程序实现了图像采集系统和运动系统的同步运行，系统的技术指标达到：扫描范围为220mm×250mm×100mm（宽度×高度×深度），典型分辨率为0.4mm×0.4mm×0.5mm（宽度×高度×深度），扫描时间为7s。

建立摄像机理想线性模型和畸变模型得到三维世界坐标和计算机图像坐标的映射关系。将张正友标定算法和摄像机透视变换矩阵标定法相结合对传感器进行标定得到了系统的内参数和外参数。

进行系统调试和实际扫描实验，得到人脸模型的三维点云，通过对点云进行二次采样使摄像机对三条光带的分辨率达到一致，对原始点云和二次采样点云进行重建得到网格模型。对标准量块进行扫描实验得到系统的相对测量误差小于0.25%。

将双目立体视觉原理与主动式激光扫描相结合，提出摄像机固定不动，利用三条线激光进行扫描的方案，获得了人脸点云图和网格模型并对三光带激光扫描和双目视觉两种方法进行了比较。

关键词：人体面部扫描 三光带 传感器标定 二次采样 双目视觉

ABSTRACT

After analysis of the 3D human face scanning technology at home and abroad, based on laser triangulation principle, in accordance with the requirements of high resolution and short scanning time, a project of three-line structured light laser 3D human face scanning has been proposed. The hardware and software of the system were designed with the key technology studied. The prototype of the system was developed successfully. Scanning experiments were carried out and the expected results verified the correctness of the system. The main work includes:

According to the actual requirements, a project of three-line structured light laser 3D human face scanning was proposed. Three parallel structured light with the same distance in the height direction were projected from three lasers in the same type. When scanning, each laser should move 1/3 of the entire scanning range which meets the requirement of reducing the scanning time of the system.

The general structure of the system were designed which included sensors, motion system, image capture system and computer processing system. The control program has been completed which realized the synchronous running of the image capture system and motion system. The technical indexes of the system reach that: scanning range of 220mm×250mm×100mm(W×H×D), typical resolution of 0.4mm×0.4mm×0.5mm(W×H×D), scanning time of 7 seconds.

By establishing the ideal linear mode and the distortion model of the camera, the mapping relationship between the 3D world coordinates and the computer image coordinates has been deduced. Zhang Zhengyou calibration algorithms and camera perspective transformation matrix calibration method were combined to carry out calibration to the sensor. The intrinsic parameters and external parameters of the system were obtained.

After debugging the system and processing the actual scanning experiment, the point cloud of the face model was obtained. By resampling of the point cloud, the camera resolution of the three-line structured light reached the same. The original point cloud and the resampling point cloud were reconstructed to receive the mesh model. By scanning the standard gauge block, the relative measurement error of the system was less than 0.25%.

By combining the binocular stereo vision and active laser scanning, a project of three-line structured light scanning with the camera fixed was proposed. Point cloud and reconstruction model of the face were obtained. The two methods of three-line structured light laser scanning and binocular vision were compared.

KEY WORDS：human face scanning, three-line structured light, sensor calibration, resampling, binocular vision

目 录

第一章 绪论1

1.1三维数据获取方法概述1

1.2面部三维测量的应用2

1.3面部三维测量的国内外研究状况3

1.4课题背景5

1.5论文主要工作及研究意义5

第二章 扫描系统的原理和总体设计6

2.1系统的扫描原理6

2.2系统的总体设计7

2.2.1 系统的技术指标7

2.2.2 系统的总体结构8

2.3系统的硬件设计9

2.3.1 传感器的设计9

2.3.2 图像采集卡的选择11

2.3.3 同步运动系统设计12

2.3.4 机械结构的设计13

2.4 系统的软件设计15

2.5本章小结18

第三章 系统的标定研究19

3.1摄像机标定方法概述19

3.1.1 传统的摄像机标定19

3.1.2 自标定技术20

3.2摄像机模型的建立20

3.2.1 摄像机理想线性模型20

3.2.2 摄像机实际非线性模型23

3.3系统的标定及结果24

3.3.1内参数的标定24

3.3.2系统的线性标定26

3.4 本章小结32

第四章 系统的调试与实验33

4.1系统的调试33

4.2 面部模型扫描实验34

4.2.1 光带中心线提取34

4.2.2光带分组34

4.2.3 面部模型点云的获取36

4.3 点云融合及重建37

4.3.1直接融合37

4.3.2 均匀采样融合39

4.3.3 网格重建40

4.4 精度验证41

4.5 本章小结45

第五章 基于激光扫描的双目立体视觉研究46

5.1 双目立体视觉传感器46

5.1.1 摄像机模型46

5.1.2立体视觉模型47

5.2 基本矩阵48

5.3 立体视觉中的极线几何50

5.4 系统结构的调整51

5.5系统标定52

5.6立体匹配53

5.7 扫描实验53

5.7.1 实验结果53

5.7.2 两种方法的比较55

5.8 本章小结55

第六章 总结与展望56

6.1 工作总结56

6.2对后续工作的建议56

参考文献57

发表论文及科研情况说明61

致 谢62