Lensless hyperspectral imaging by Fourier transform spectroscopy for broadband visible light: phase retrieval technique

Spectral DiffuserCam: lensless snapshot hyperspectral imaging with a spectral filter array

Hyperspectral imaging is useful for applications ranging from medical diagnostics to agricultural crop monitoring; however, traditional scanning hyperspectral imagers are prohibitively slow and expensive for widespread adoption. Snapshot techniques exist but are often confined to bulky benchtop setups or have low spatio-spectral resolution. In this paper, we propose a novel, compact, and inexpensive computational camera for snapshot hyperspectral imaging. Our system consists of a tiled spectral filter array placed directly on the image sensor and a diffuser placed close to the sensor. Each poi…

Untrained networks for compressive lensless photography

Compressive lensless imagers enable novel applications in an extremely compact device, requiring only a phase or amplitude mask placed close to the sensor. They have been demonstrated for 2D and 3D microscopy, single-shot video, and single-shot hyperspectral imaging; in each of these cases, a compressive-sensing-based inverse problem is solved in order to recover a 3D data-cube from a 2D measurement. Typically, this is accomplished using convex optimization and hand-picked priors. Alternatively, deep learning-based reconstruction methods offer the promise of better priors, but require many tho…

MetaSpectra+: 一种紧凑型宽频带超表面相机用于快照超光谱+成像

MetaSpectra+: A Compact Broadband Metasurface Camera for Snapshot Hyperspectral+ Imaging

MetaSpectra+是一种紧凑型宽频带超表面相机，能实现快照HDR+超光谱或偏振+超光谱成像，具有最短跟踪长度和最高重建精度。

ADMM and Spectral Proximity Operators in Hyperspectral Broadband Phase Retrieval for Quantitative Phase Imaging

A novel formulation of the hyperspectral broadband phase retrieval is developed for the scenario where both object and modulation phase masks are spectrally varying. The proposed algorithm is based on a complex domain version of the alternating direction method of multipliers (ADMM) and Spectral Proximity Operators (SPO) derived for Gaussian and Poissonian observations. Computations for these operators are reduced to the solution of sets of cubic (for Gaussian) and quadratic (for Poissonian) algebraic equations. These proximity operators resolve two problems. Firstly, the complex domain spectr…

基于反射结构的宽带近红外压缩光谱成像系统

Broadband Near-Infrared Compressive Spectral Imaging System with Reflective Structure

针对传统近红外高光谱成像系统成本高、体积大、数据采集效率低的问题，本研究提出基于反射结构的宽带近红外压缩光谱成像系统，通过波长分割和专用光学组件设计实现700-1600 nm宽带数据捕获且系统紧凑，为近红外高光谱成像提供新方案。

Polarized hyperspectral imaging with single fiber bundle via incoherent light transmission matrix approach

The scattering of multispectral incoherent light is a common and unfavorable signal scrambling in natural scenes. However, the blurred light spot due to scattering still holds lots of information remaining to be explored. Former methods failed to recover the polarized hyperspectral information from scattered incoherent light or relied on additional dispersion elements. Here we put forward the transmission matrix (TM) approach for extended objects under incoherent illumination by speculating the unknown TM through experimentally calibrated or digitally emulated ways. Employing a fiber bundle as…