Terahertz high-resolution rapid imaging device based on block compressed sensing

Abstract

The invention discloses a terahertz high-resolution rapid imaging device based on block compressed sensing, which comprises the following steps of: the terahertz wave generated by the terahertz radiation source passes through a square aperture to define a beam size, and the terahertz wave is incident to the imaging object at a vertical angle; the imaging object and the metal mask plate are placedin parallel in an optical path; the imaging object is sequentially placed in the optical path under the driving of the two-dimensional displacement platform, light waves with the imaging object information are received and measured by the terahertz wave detector after transmission modulation of the metal mask plate, and a reconstructed image of the part of the imaging object can be obtained by inputting the obtained data into a compressed sensing reconstruction program; and after all the blocks of the imaging object are placed in the optical path and imaging, the whole imaging result can be obtained by splicing the images of all the blocks according to the corresponding order on the complete image. According to the terahertz high-resolution rapid imaging device based on block compressed sensing, block imaging the object to be tested and re-splicing to realize the image reconstruction by means of the matrix modulation wide beam, avoiding the problem of the detector saturation and the decline of the calculation efficiency of the reconstruction algorithm.

Description

technical field [0001] The present invention relates to the field of terahertz wave imaging, in particular to a terahertz high-resolution fast imaging device based on block compressed sensing. Background technique [0002] Terahertz wave is a general term for electromagnetic waves with frequencies in the range of 0.1-10 THz, and electromagnetic waves in this frequency range have some unique properties. The high penetration of terahertz waves to non-polar substances allows them to be used in security checks, anti-terrorism and other related fields; the low photon energy of terahertz waves makes them less harmful to human tissues than X-rays, and can be used in biological It also has broad application prospects in the medical field. Imaging technology is an important application field of terahertz waves. At present, more mature terahertz imaging technologies include point-by-point scanning imaging and array imaging. Point-by-point scanning imaging usually uses a single-pixel...

AI Technical Summary

Problems solved by technology

[0004] Since the light intensity received by the single-pixel detector is the intensity superposition of all light-transmitting units after modulation, the imaging resolution is limited by the size of the mask matrix

In addition, when the number of light-transmitting units is large, the detector may be saturated due to excessive intensity, and when the amount of data is too large, the computational efficiency of the reconstruction algorithm will be greatly reduced and the imaging speed will be reduced

The existing single-pixel random sampling block compression imaging system needs to simulate and calculate different imaging objects in advance, determine the sampling position in the experiment according to the calculation results, and inject the terahertz focused spot into the designated position of the sample, and the collected Data is compressed sensing imaging, the defect is that each collected data cannot include the global information of the image, when the selected sampling points are inappropriate, it will lead to poor imaging results

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