Design And Development Of A Snapshot Hyperspectral Camera

Hyperspectral Imaging?HSI?is a newly developing technology,which properly combines the traditional two-dimensional imaging with spectrum spectroscopy for the acquisition of data cube.Because it has many competitive advantages of space identifiable,super multiband and high spectral resolution,so it can be applied to areas such as atmosphere,food,drug safety detection,etc.Snapshot HSI can obtain all the target's information of two-dimensional space and one-dimensional spectrum through once exposure.Snapshot HSI possesses the distinctive advantages of excellent imaging speed and allowing real-time monitoring.The primary tasks for the design and development of the Snapshot HSI camera in this paper are as follows:1.Hardware Design:The requirement analysis,light path design and confirmation of the component parameter for the Snapshot HSI system had been conducted.Then the prototype of the system had been built successfully.2.Correction and Calibration:The pincushion distortion of the projected images had been corrected through the method of equivalent curved surface model.Then the technical parameters had been calibrated,such as the wavelength,the spectral response functions of each channel,the spectral resolution,the image space resolution,the spectral response range,and so on.3.HDR?High Dynamic Range?Image Acquisition:The HDR image acquisition mode had been adopted to have enough optical sensitivity and light dynamic range,and multi-exposure image fusion algorithm had been applied to acquire the high dynamic range image.4.Data Reconstruction:The EM?Expectation Maximization?algorithm and system matrix H had been used to reconstruct the three-dimensional cube.The reconstruction result was satisfactory.In this paper,a Snapshot HSI system based on industrial camera had been successfully designed and developed by the correction of pincushion distortion,the calibration of the system technical parameters and the introduction of HDR image acquisition mode.This system solves the inherent problems like the limited dynamic range and the rather loud noise of the industrial cameras.The spectral resolution of this system is 2.3 nm,the image space resolution is 320?320 pixel,the spectral response range is 420⁶80 nm and the image dynamic range is 0²¹⁴.In this paper,the preliminary work for the instrument development had been completed.However,to achieve the real-time monitoring,alerting in industry zone,the algorithm still needs to be optimized and the user-oriented control and analysis software needs to be developed.