Compressive Spectral Imaging via Misalignment Induced Equivalent Grayscale Coded Aperture

Journal Title
Journal ISSN
Volume Title
IEEE Geoscience and Remote Sensing Letters
Coded aperture snapshot spectral imager (CASSI) senses the spectral information of a 2-D scene and captures a set of coded measurement data that can be used to reconstruct the 3-D spatio-spectral datacube of the input scene by compressive sensing algorithms. The coded aperture (CA) in CASSI plays a crucial role in modulating the spatial information. The pixels in CA are typically square, switched binary ON–OFF, and aligned with the pixels of focal plane array (FPA). Instead of this binary modulation, this letter explores a simple yet effective approach to enabling an equivalent grayscale modulation, which can increase the sensing degree of freedom in CASSI systems. In particular, we deliberately introduce misalignment between the CA pixels and the FPA pixels, such that the spatial modulation of one FPA pixel is determined by four adjacent CA pixels instead of one. Numerical experiments show that the proposed equivalent grayscale modulation induced by misalignment can significantly improve the CASSI reconstruction when compared with current methods, whether a random CA or an optimal blue noise CA is used. More importantly, it does not incur in any cost to the CASSI system.
© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This article was originally published in IEEE Geoscience and Remote Sensing Letters. The version of record is available at:
coded aperture (CA) imaging, computational imaging, multispectral and hyperspectral imaging
T. Zhang, S. Zhao, X. Ma, A. Ramirez-Jaime, Q. Zhao and G. R. Arce, "Compressive Spectral Imaging via Misalignment Induced Equivalent Grayscale Coded Aperture," in IEEE Geoscience and Remote Sensing Letters, vol. 20, pp. 1-5, 2023, Art no. 5503005, doi: 10.1109/LGRS.2023.3247799.