基于离散外极曲线模型的水下多线结构光双目测量方法  

Underwater Multiple Line-Structured Light Binocular Measuring Method Based on Discrete Epipolar Curve Model

作　　者：解则晓[1] 邵玮婧 高翔[1] 宫韩磊 王皓月 焦雨庆 Xie Zexiao;Shao Weijing;Gao Xiang;Gong Hanlei;Wang Haoyue;Jiao Yuqing(College of Engineering,Ocean University of China,Qingdao,Shandong 266100,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100

出　　处：《中国激光》2021年第13期102-112,共11页Chinese Journal of Lasers

基　　金：国家自然科学基金(42076192,62003319);山东省自然科学基金(ZR2020QF075);青岛市博士后应用研究项目。

摘　　要：采用非平行双目视觉测量系统对水下目标进行测量时,水对光线的折射使传统外极线约束关系不再成立,导致系统的测量误差较大。为了进一步提高系统的测量精度,提出了一种基于多线结构光的水下双目视觉测量方法。该方法基于水下非平行双目视觉测量系统模型和光线追踪原理建立了水下外极线离散曲线模型,并提出了一种用于特征点匹配的水下外极线匹配方法,以实现水下目标的三维测量。实验结果表明,本方法可以有效实现多结构光的光条立体匹配,提高水下目标的测量精度。Objective When the binocular vision system is used to measure underwater targets, the refraction effect of water makes the measurements differ from the actual situation. The existing methods for reducing the refraction effect include the following. 1) A high-accuracy refraction model is established for calculating the refraction path of each pixel in the camera using the model and for obtaining the actual position of the pixel. 2) The refraction effect is assumed to be an aberration of the camera model. Furthermore, a new camera-calibration method is used to estimate the camera parameters in the underwater environment through which a new measurement model is established to reduce the refraction effect. 3) By improving the traditional epipolar line-based matching method, the traditional onshore epipolar line model can be applied to underwater situations for feature point matching. However, these three methods have certain limitations. 1) High-order parameters need to be introduced when establishing a high-accuracy refraction model, making the calculation process more complex. 2) Special calibration devices are used for camera calibration to compensate for the refraction effect of water. Although an accurate underwater refraction model can be obtained using this method, the calibration devices are usually complex. 3) Although the matching method of the traditional epipolar line exhibits good practicability, the refraction effect on the epipolar line is not considered. Herein, we propose a new modeling method of underwater epipolar line using a device containing multiple line-structured light and a binocular vision system. The discrete curve model of the underwater epipolar line is established based on the ray-tracing principle. In addition, the underwater epipolar line-matching method is improved for feature point matching. The method can effectively improve the matching accuracy of underwater feature points and further improve the measurement accuracy of underwater targets.Methods Herein,the objects of measurement

关 键 词：测量与计量 机器视觉 组织中光传播 光路折射 

分 类 号：TN2[电子电信—物理电子学]