High resolution snapshot imaging spectrometer using a fusion algorithm based on grouping principal component analysis

Abstract

We reported a high resolution snapshot imaging spectrometer (HR-SIS) and a fusion algorithm based on the properties of the HR-SIS. The system consists of an imaging branch and a spectral branch. The imaging branch captures a high spatial resolution panchromatic image with 680 × 680 pixels, while the spectral branch acquires a low spatial resolution spectral image with spectral resolution of 250 cm^-1. By using a fusion algorithm base on grouping principal component analysis, the spectral image is highly improved in spatial resolution. Experimental results demonstrated that the performance of the proposed algorithm is competitive with other state-of-the-art algorithms. The computing time for a single frame is less than 1 min with an Intel Core i5-4200H CPU, which can be further reduced by utilizing a graphics processing unit (GPU).

Plenoptic Face Presentation Attack Detection

“…Simply put, we first trained a CNN architecture including two hidden layers and an output layer to decouple the light-field image (x,y,θ, ϕ) and interference from a raw image. Then we reconstructed the depth map (x,y,z) from the light-field image using a disparity estimation algorithm based on scale-depth space transform [27], while a 3D spectral datacube (x,y,λ) of the subject was derived from the interference by Fourier transform [28], [29]. We thoroughly described the theoretical model and reconstruction algorithm of the complete plenoptic imaging in Ref [25].…”

“…It is noteworthy that we use a different BPI configuration from the one used in the previous system [25]-the Wollaston prism is replaced by two NPs and an HWP [28], [29]. Therefore, a real interference plane is formed outside the BPI, co-located with the elemental image array formed by the MLA.…”

Application of snapshot imaging spectrometer in environmental detection

“…It contains the imaging branch and the spectral branch based on a SHIFT spectrometer. The optical path difference is generated by changing the refractive index of the optical transmission medium by using the spatial modulation method based on the birefringent crystal interferometer [12] . The interference information is acquired by means of the snapshot, the aperture is segmented by the micro lens array, and the complete interference image of the target to be measured is obtained in a shutter time.…”