光场成像技术研究及其在激光参数测量中的应用

发布时间：2018-05-31 14:16

本文选题：光场成像 + 深度提取　；参考：《中国科学院研究生院(西安光学精密机械研究所)》2015年博士论文

【摘要】：与传统成像相比,光场成像技术可实现空间四维光场信息的采集,通过光场重构算法可获取空间三维信息。目前国内的研究主要集中在非聚焦型光场成像及三维视点重构领域,对于聚焦型光场成像的理论研究工作还处于初步阶段,需要更加深入的研究。本文主要围绕聚焦型光场成像系统的工作原理、重构算法设计、结构设计及光场成像技术在激光参数测量中的应用四个问题展开研究,主要内容如下:1、根据光场成像理论,建立了不同采样模式下光场传输、记录及重构的数学模型。根据微透镜阵列的光场采样规律,提出了聚焦型光场成像的点扩散函数加权重构算法,该算法解决了分块重构算法重构图像中离焦区域中重构边界的阶梯效应。针对点扩散加权重构,本文设计了一种运算量少、重构精度高的权重函数。将该权重函数与本文提出的点扩散函数重构算法相结合,完成高精度光场图像重构算法设计及验证。2、利用光场成像系统具有记录物体视差的特性,建立了一种根据目标在上下左右四个方向的视差来计算目标深度图的方法。以目标在深度图中的深度作为对焦搜索初始值,设计了一种快速对焦搜索算法——两步法(即:先根据深度图确定初始搜索位置,再根据对焦搜索算法搜索对焦位置),该算法可实现指定目标的快速对焦,且具有良好的抗噪特性。展开本文两步法光场对焦与普通对焦搜索之间的对比实验,验证了该方法的搜索准确性及省时特性。3、根据聚焦型光场成像光学结构参数与光场重构参数之间的数学关系,设计了聚焦型光场成像系统并开展了系统仿真验证,完成了聚焦型光场成像系统整机搭建,完成了微透镜与探测器倾斜量的标定工作。开展了聚焦型光场成像系统的成像实验及实验数据分析,实验结果验证了本文设计理论的准确性及可靠性。4、总结目前激光参数测量领域的问题,提出了基于双楔板阵列的激光动态焦斑测试系统,完成单脉冲激光远场光斑漂移测量。开展了基于聚焦型光场成像技术的激光参数量测量实验,实现了基于光场技术的远场焦斑位置测量及三维重构。
[Abstract]:Compared with the traditional imaging, the optical field imaging technology can realize the acquisition of spatial four-dimensional light field information, and the three-dimensional spatial information can be obtained by the light field reconstruction algorithm. At present, the domestic research is mainly focused on the field of unfocused light field imaging and 3D view reconstruction. The theoretical research of focused light field imaging is still in the initial stage, and needs more in-depth research. This paper mainly focuses on the working principle, reconstruction algorithm design, structure design and the application of light field imaging technology in laser parameter measurement. The main contents are as follows: 1, according to the theory of light field imaging, A mathematical model of light field transmission, recording and reconstruction in different sampling modes is established. According to the law of light field sampling of microlens array, a point diffusion function weighted reconstruction algorithm for focused light field imaging is proposed. The algorithm solves the step effect of reconstruction boundary in defocus region of image reconstruction by block reconstruction algorithm. For point diffusion weighted reconstruction, this paper designs a weight function with less computation and higher reconstruction precision. The weight function is combined with the point diffusion function reconstruction algorithm proposed in this paper to complete the design and verification of the high precision light field image reconstruction algorithm. The optical field imaging system has the property of recording the parallax of the object. A method to calculate the depth map of the target is established according to the parallax of the target in four directions. Taking the depth of the target in the depth map as the initial value of the focal search, a fast focusing search algorithm, a two-step method, is designed (that is, the initial search position is first determined according to the depth map). Then the focus location is searched according to the focusing search algorithm. The algorithm can realize the fast focusing of the specified target and has good anti-noise characteristic. In this paper, the contrast experiment between the two step method and ordinary focus search is carried out, and the accuracy and time-saving characteristic of the method are verified. 3. According to the mathematical relationship between the optical structure parameters of focused light field imaging and the parameters of light field reconstruction, The focused light field imaging system is designed and the system simulation is carried out. The whole machine of the focused light field imaging system is built and the calibration of the tilt between the microlens and the detector is completed. The imaging experiments and experimental data analysis of focused light field imaging system are carried out. The experimental results verify the accuracy and reliability of the design theory in this paper. The problems in the field of laser parameter measurement are summarized. A laser dynamic focal spot measurement system based on double wedge array is proposed to measure the far field spot drift of monopulse laser. The experiment of laser parameter measurement based on focused light field imaging technology is carried out. The far-field focal spot position measurement and 3D reconstruction are realized based on light field technology.
【学位授予单位】：中国科学院研究生院(西安光学精密机械研究所)
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TP391.41

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