Generalized snapshot spectral imaging across different illuminants with wavelength-phase joint coding

Snapshot spectral imaging has been an active area of research and has attracted significant attention. However, few studies have considered the diversity of light sources, leading to overfitting on specific types of illuminants. In this paper, we propose an illuminant augmentation method to improve the generalization ability. The color filter arrays (CFAs) of RGB cameras can encode wavelength information to colors but meet metamerism. To tackle this issue, we further optimize a diffractive optics element (DOE) for phase coding in an end-to-end manner. We build a phase-wavelength joint coding compressive imaging system that shows better generalization ability than a conventional RGB camera. To enhance the spectral reconstruction performance, we introduce a novel mamba-based network, snapshot spectral compressive imaging mamba (SSCIM). Additionally, we have collected a well-calibrated hyperspectral dataset of relative reflectance for testing. Experimental results demonstrate that our method achieves state-of-the-art performance in hyperspectral reconstruction and illuminant generalization.