基于平场光栅的稀疏约束鬼成像光谱相机研究
文献类型：学位论文
| 作者 | 刘盛盈 |
| 文献子类 | 硕士 |
| 导师 | 韩申生 |
| 关键词 | 光谱成像 spectral imaging 鬼成像 ghost imaging 压缩感知 compressed sensing 平场光栅 flat-field grating |
| 其他题名 | A hyperspectral camera based on ghost imaging via sparsity constraints with a flat-field grating |
| 英文摘要 | 光谱成像技术是将光谱分析与成像合二为一的光学多维数据探测技术。自从 20 世纪 80 年代，光谱成像的思想首次被提出以来，由于其能够获得目标场景的三维数据立方体，使得其被广泛应用于军事安全，环境监测，生物科学，医学诊断，科学观察等诸多领域。传统鬼成像的信号采样模式与压缩感知理论（ CS）相吻合，因此利用图像的稀疏特性，可以将两者有机的结合在一起，形成基于稀疏和冗余表象的鬼成像（ Ghost Imaging via Sparsity Constraints，GISC）技术，其能够突破奈奎斯特采样定理，有效地提高采样效率，同时又具备了鬼成像技术探测灵敏度高等一系列优点。同时将上述的 GISC 理论与当前光谱成像技术中的研究热点——快照光谱成像（ snapshot spectral imaging）技术相结合，便是本文所要介绍的基于平场光栅的稀疏约束鬼成像光谱相机理论。此系统采用平场光栅作为分光色散模块， 使得不同波长的光场在空间上分离，然后经过空间随机相位调制器的调制产生散斑场， 将三维光谱图像数据立方体调制成沿光谱维展开的二维数据平面，从而可以通过二维探测器记录光谱分辨率和空间分辨率独立可调的全谱段光谱图像信息。此光谱相机具有高的能量利用率和信号采样率，成像时间短，同时将光谱分辨率与空间分辨率解耦可调，使得其在日后的工程实用中具有重大的应用前景。 本文的内容主要包括为： 第 1 章，由于基于平场光栅的稀疏约束鬼成像（ GISC） 光谱相机是将光谱成像技术，鬼成像技术，压缩感知理论三者相结合的成像方式，因此本章中首先简单介绍了光谱成像技术的相关理论及其分类， 其中着重阐述了与本文相关的快照光谱成像（ snapshot spectral imaging） 技术的发展历程，然后说明了光谱成像技术在实际应用中的发展历史及其未来的发展趋势。接着又简单地介绍了鬼成像技术和压缩感知理论的基本概念以及发展历程。 第 2 章，为了使得系统的空间分辨率和光谱分辨率得到解耦，在原有的GISC 光谱相机的系统里加入平场光栅作为色散元件。因此本章首先介绍了传统光谱成像技术中最为常见的两种色散元件——棱镜和光栅，着重阐述了使用光栅作为色散元件的分光方式及其发展历程，引出了本文采用的色散元件——平场光栅。接着便简单地介绍了平场光栅的色散和成像原理，以及其相关技术的发展情况与趋势。在此基础上，便提出了基于平场光栅的稀疏约束鬼成像光谱相机的系统方案，从理论上推导了系统的成像模型，并分析和对比了此系统 与未加入色散模块的系统的光谱分辨率和空间分辨率，发现加入色散模块后系统的光谱分辨率得到较大的提高，而其空间分辨率基本未受影响。 第 3 章， 为了验证理论推导结果的准确性以及此系统方案的可行性， 则需要通过实验与数值模拟的方法。 本章首先介绍了实验平台的搭建以及实验数据的获得，通过对获得的实验数据的处理得到了系统的光谱分辨率与空间分辨率，并与理论推导得到的结果进行了对比，在误差允许范围内， 理论结果与实验结果吻合得较好， 验证了理论的准确性。 然后采用实验得到的测量矩阵进行了数值模拟， 说明了此成像方案在实际成像实验中的可行性。最后搭建了基于平场光栅的 GISC 光谱相机的实验平台，并初步完成了实物目标的成像实验。 第 4 章，论文的总结以及未来的展望。; Spectral imaging technology is an optical multidimensional data detection technology which is a combination of spectral analysis and imaging. Because the spectral imaging can obtain the three-dimensional data cube of the target scene, it has been widely used in military security, environmental monitoring, biological sciences, medical diagnosis, scientific observation and many other areas since 1980s when the idea of spectral imaging has been proposed for the first time. The signal sampling mode of the traditional ghost imaging matches compression sensing (CS). Therefore, both of them can be organically combined by the sparseness of the image to form the technology of the ghost imaging via sparsity constraints, which can break through the Nyquist sampling theorem, improve sampling efficiency, and have high detection sensitivity of the ghost imaging and so on. Meanwhile, combining the above GISC theory with the research hotspot—snapshot spectral imaging technology in the current spectral imaging technology is the theory of the hyperspectral camera based on ghost imaging via sparsity constraints with a flat-field grating which is introduced in this thesis. We use a flat-field grating as a spectral dispersion module, so that different wavelengths of light field can be separated in the space, and then the light field is modulated by a spatial random phase modulator to produce speckle field, which make the 3D spectral images data-cube be modulated into a two-dimensional (2D) data plane and the camera achieve the whole wavelength image whose spatial resolution and spectral resolution can be independently adjustable. The spectral camera has high energy utilization and signal sampling rate as well as short imaging time, meanwhile the spectral resolution and spatial resolution are decoupled. Therefore the camera has great application prospects in the future engineering. The main contents of this thesis are as follows: Chapter 1, The hyperspectral camera based on ghost imaging via sparsity constraints (GISC hyperspectral camera) with a flat-field grating is an imaging technology combining spectral imaging technology, ghost imaging technology and compression sensing theory, hence, we first introduce the theory and classification of the spectral imaging in this thesis, which is mainly about the development of snapshot spectral imaging. And then the history and development of the spectral imaging in practical application is described. Finally, the thesis introduces the basic concepts and development process of ghost imaging and compression sensing. Chapter 2, In order to decouple spatial and spectral resolution, a flat-field grating is put in the original GISC system to be as a dispersion element. Therefore, two common dispersion elements in traditional spectral imaging technology, prism and grating, are introduced in the chapter firstly, which is mainly about spectroscopic methods and development of grating to lead to dispersion element—a flat-field grating. And then we introduce the dispersion and imaging theory of the flat-field grating, as well as its development and trend. On this basis a system scheme of GISC hyperspectral camera with a flat-field grating is proposed. We deduced the theoretical model of the imaging system, and compare the spatial and spectral resolution of this system with those of the system without a dispersion module. Then it finds that the spectral resolution of the system with dispersion is improved under almost the same spatial resolution. Chapter 3, The accuracy of the theoretical derivation and the feasibility of the system are needed to be verified by experiment and numerical simulations. In this chapter, we first introduce the construction of the experimental platform and the acquisition of the experimental data. The spectral resolution and the spatial resolution of the system are obtained by dealing with the obtained experimental data, and then the results of the experiment are compared with the theoretical results to verify the accuracy of the theory. Within the allowable range of error, the theoretical result agrees well with the experimental result. On this bias, numerical simulation is adopted according to measurement matrix obtained by experiment to verify that this imaging scheme is feasible in actual imaging experiment. Finally, an imaging experiment is carried out by GISC spectral camera with a flat field grating. Chapter4, The conclusion of this thesis and the future prospects. |
| 学科主题 | 光学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/30922]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 刘盛盈. 基于平场光栅的稀疏约束鬼成像光谱相机研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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