Enhancement of CASSI by a zero-order image employing a single detector

Coded aperture snapshot spectral imaging (CASSI) makes it possible to recover 3D hyperspectral data from a single 2D image. However, the reconstruction problem is severely underdetermined, and efforts to improve the compression ratio typically make the imaging system more complex and cause a significant loss of incoming light intensity. In this paper, we propose a novel approach to CASSI that enables capturing both a spectrally sheared and an integrated image of a scene with a single camera. We performed hyperspectral imaging of three different testing scenes in the spectral range of 500-900 nm. We demonstrate the prominent effect of using the nondiffracted image on the reconstruction of data from our camera. The use of the spectrally integrated image improves the reconstruction quality, and we observed an approximately fivefold reduction in reconstruction time.