Sippel Frank, Seiler Jürgen, Kaup André
J Opt Soc Am A Opt Image Sci Vis. 2024 Dec 1;41(12):2303-2315. doi: 10.1364/JOSAA.536572.
Retrieving the reflectance spectrum from objects is an essential task for many classification and detection problems, since many materials and processes have a unique spectral behavior. In many cases, it is highly desirable to capture hyperspectral images due to the high spectral flexibility. Often, it is even necessary to capture hyperspectral videos or at least to be able to record a hyperspectral image at once, also called snapshot hyperspectral imaging, to avoid spectral smearing. For this task, a high-resolution snapshot hyperspectral camera array using a hexagonal shape is introduced. The hexagonal array for hyperspectral imaging uses off-the-shelf hardware, which enables high flexibility regarding employed cameras, lenses, and filters. Hence, the spectral range can be easily varied by mounting a different set of filters. Moreover, the concept of using off-the-shelf hardware enables low prices in comparison to other approaches with highly specialized hardware. Since classical industrial cameras are used in this hyperspectral camera array, the spatial and temporal resolution is very high, while recording 37 hyperspectral channels in the range from 400 to 760 nm in 10 nm steps. As the cameras are at different spatial positions, a registration process is required for near-field imaging, which maps the peripheral camera views to the center view. It is shown that this combination using a hyperspectral camera array and the corresponding image registration pipeline is superior in comparison to other popular snapshot approaches. For this evaluation, a synthetic hyperspectral database is rendered. On the synthetic data, the novel approach, to our knowledge, outperforms its best competitor by more than 3 dB in reconstruction quality. This synthetic data is also used to show the superiority of the hexagonal shape in comparison to an orthogonal-spaced one. Moreover, a real-world high-resolution hyperspectral video database with 10 scenes is provided for further research in other applications.
从物体中获取反射光谱是许多分类和检测问题的一项基本任务，因为许多材料和过程都具有独特的光谱行为。在许多情况下，由于光谱具有高度灵活性，因此非常希望捕获高光谱图像。通常，甚至有必要捕获高光谱视频，或者至少能够一次性记录高光谱图像，即所谓的快照高光谱成像，以避免光谱模糊。针对这项任务，本文介绍了一种采用六边形形状的高分辨率快照高光谱相机阵列。用于高光谱成像的六边形阵列使用现成的硬件，这使得在使用相机、镜头和滤光片方面具有很高的灵活性。因此，通过安装不同的滤光片组可以轻松改变光谱范围。此外，与其他使用高度专业化硬件的方法相比，使用现成硬件的概念使得成本较低。由于该高光谱相机阵列中使用了传统工业相机，因此在记录400至760nm范围内以10nm步长的37个高光谱通道时，空间和时间分辨率非常高。由于相机处于不同的空间位置，近场成像需要进行配准过程，即将周边相机视图映射到中心视图。结果表明，与其他流行的快照方法相比，这种使用高光谱相机阵列和相应图像配准管道的组合具有优势。为了进行此评估，生成了一个合成高光谱数据库。据我们所知，在合成数据上，这种新方法在重建质量上比其最佳竞争对手高出3dB以上。该合成数据还用于展示六边形形状相对于正交间隔形状的优越性。此外，还提供了一个包含10个场景的真实世界高分辨率高光谱视频数据库，以供其他应用的进一步研究使用。
