Galvis Laura, Mojica Edson, Arguello Henry, Arce Gonzalo R
Appl Opt. 2019 Mar 1;58(7):B28-B38. doi: 10.1364/AO.58.000B28.
Compressive spectral imaging (CSI) systems sense 3D spatio-spectral data cubes with just a few two-dimensional (2D) projections by using a coded aperture, a dispersive element, and a focal plane array (FPA). The coded apertures in these systems, whose main function is the modulation of the data cube, are often implemented through photomasks attached to piezoelectric devices. A remarkable improvement on this configuration has been recently proposed, the replacement of the block-unblock coded apertures by patterned optical filter arrays, referred to as "colored" coded apertures, which allow spatial and spectral modulation. When using these colored coded apertures, its real implementation in terms of cost and complexity directly depends on the number of filters to be used, as well as the number of shots to be captured. A shifting colored coded aperture optimization featuring these observations is proposed, with the aim to improve the imaging quality reconstruction and to generate an achievable optical implementation with a limited number of filters requiring only one mask to acquire any number of shots. The mathematical model of the computational imaging strategy to overcome the practical limitations of actual CSI systems is presented along with a testbed implementation. Simulations, as well as experimental results, will prove the accuracy and performance of the proposed shifting colored coded aperture design over the current literature designs.
压缩光谱成像（CSI）系统通过使用编码孔径、色散元件和焦平面阵列（FPA），仅通过几次二维（2D）投影就能感知三维空间光谱数据立方体。这些系统中的编码孔径主要功能是对数据立方体进行调制，通常通过附着在压电设备上的光掩膜来实现。最近有人提出了对这种配置的显著改进，即用图案化光学滤波器阵列取代分块-非分块编码孔径，即所谓的“彩色”编码孔径，它可以实现空间和光谱调制。在使用这些彩色编码孔径时，其在成本和复杂性方面的实际实现直接取决于要使用的滤波器数量以及要采集的拍摄次数。本文提出了一种基于这些观察结果的移动彩色编码孔径优化方法，旨在提高成像质量重建，并生成一种可行的光学实现方案，该方案使用有限数量的滤波器，仅需一个掩膜就能采集任意数量的拍摄图像。本文介绍了克服实际CSI系统实际限制的计算成像策略的数学模型以及试验台实现。仿真和实验结果将证明所提出的移动彩色编码孔径设计相对于当前文献设计的准确性和性能。
