scholarly journals Adaptive Single Photon Compressed Imaging Based on Constructing a Smart Threshold Matrix

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3449
Author(s):  
Wentao Shangguan ◽  
Qiurong Yan ◽  
Hui Wang ◽  
Chenglong Yuan ◽  
Bing Li ◽  
...  
Keyword(s):  
Random Matrix ◽  
Adaptive Sampling ◽  
Imaging System ◽  
Single Photon ◽  
A Priori ◽  
Photon Counting ◽  
Reconstruction Algorithms ◽  
Measurement Matrix ◽  
Adaptive Imaging ◽  
Adaptive Measurement

We demonstrate a single-photon compressed imaging system based on single photon counting technology and compressed sensing theory. In order to cut down the measurement times and shorten the imaging time, a fast and efficient adaptive sampling method, suited for single-photon compressed imaging, is proposed. First, the pre-measured rough images are transformed into sparse bases as a priori information. Then a smart threshold matrix is designed by using large sparse coefficients of the rough image in sparse bases. The adaptive measurement matrix is obtained by modifying the original Gaussian random matrix with the specially designed threshold matrix. Building the adaptive measurement matrix requires only one level of sparse representation, which means that adaptive imaging can be achieved quickly with very little computation. The experimental results show that the reconstruction effect of the image measured using the adaptive measurement matrix is obviously superior than that of the Gaussian random matrix under different measurement times and different reconstruction algorithms.

scholarly journals Measurement Matrix Construction for Large-area Single Photon Compressive Imaging

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 474
Author(s):  
Hui Wang ◽  
Qiurong Yan ◽  
Bing Li ◽  
Chenglong Yuan ◽  
Yuhao Wang
Keyword(s):  
Image Reconstruction ◽  
Imaging System ◽  
Single Photon ◽  
Photon Counting ◽  
Compressive Sampling ◽  
Measurement Matrix ◽  
Compressive Imaging ◽  
Sampling Ratio ◽  
Reconstruction Quality ◽  
M Sequence

We have developed a single photon compressive imaging system based on single photon counting technology and compressed sensing theory, using a photomultiplier tube (PMT) photon counting head as the bucket detector. This system can realize ultra-weak light imaging with the imaging area up to the entire digital micromirror device (DMD) working region. The measurement matrix in this system is required to be binary due to the two working states of the micromirror corresponding to two controlled elements. And it has a great impact on the performance of the imaging system, because it involves modulation of the optical signal and image reconstruction. Three kinds of binary matrix including sparse binary random matrix, m sequence matrix and true random number matrix are constructed. The properties of these matrices are analyzed theoretically with the uncertainty principle. The parameters of measurement matrix including sparsity ratio, compressive sampling ratio and reconstruction time are verified in the experimental system. The experimental results show that, the increase of sparsity ratio and compressive sampling ratio can improve the reconstruction quality. However, when the increase is up to a certain value, the reconstruction quality tends to be saturated. Compared to the other two types of measurement matrices, the m sequence matrix has better performance in image reconstruction.

Single photon counting x-ray imaging system using a micro hole and strip plate

2007 ◽  
Author(s):  
Hugo Natal da Luz ◽  
Carlos A. B. Oliveira ◽  
Carlos D. R. Azevedo ◽  
Jamil A. Mir ◽  
Joaquim M. F. dos Santos ◽  
...  
Keyword(s):  
Imaging System ◽  
Single Photon ◽  
Photon Counting ◽  
Single Photon Counting ◽  
X Ray ◽  
X Ray Imaging ◽  
Micro Hole ◽  
Strip Plate

Time-resolved imaging of fluorescent inclusions in optically turbid medium — phantom study

2010 ◽  
Vol 18 (1) ◽  
Author(s):  
M. Kacprzak ◽  
A. Liebert ◽  
P. Sawosz ◽  
N. Żołek ◽  
D. Milej ◽  
...  
Keyword(s):  
Optical Properties ◽  
Imaging System ◽  
Single Photon ◽  
Photon Counting ◽  
Turbid Medium ◽  
Time Resolved ◽  
Excitation Light ◽  
Time Resolved Imaging ◽  
Fish Tank ◽  
Surrounding Liquid

AbstractWe present results of application of a time-resolved optical system for imaging of fluorescence excited in an inclusion containing indocyanine green (ICG), and located in optically turbid medium. The developed imaging system enabled simultaneous acquisition of fluorescence and diffusive reflectance. Eight independent time-resolved measurement channels based on time-correlated single photon counting technique were applied. In four of these channels, used for the fluorescence detection, sets of filters were applied in order to block the excitation light. Fast optomechanical switches allowed us to illuminate sequentially nine different spots on the surface of the studied object and finally 4×4 pixels maps at excitation and emission wavelengths were obtained. A liquid phantom used in this study consists of the fish tank filed with a solution ofmilk and water with black ink added to obtain optical properties in the range of the optical properties typical for the living tissue. A gel ball of a diameter of 5 mm with precisely controlled concentration of ICG was immersed in the liquid. The measurements were performed for inclusion located at different depths and for various ICG concentrations in the gel ball and in the surrounding liquid. The recorded distributions of times of arrival (DTA) of fluorescence photons and times of flight (DTOF) of diffusely reflected photons were analyzed by calculation of their statistical moments. We observed specific changes in moments of the measured DTAs as a function of depth of immersion of the fluorescent inclusion in the medium. We noted also that the changes of moments depend significantly on concentration of the dye in the fluorescence inclusion as well as in the surrounding liquid.

scholarly journals Custom-Technology Single-Photon Avalanche Diode Linear Detector Array for Underwater Depth Imaging

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4850
Author(s):  
Aurora Maccarone ◽  
Giulia Acconcia ◽  
Ulrich Steinlehner ◽  
Ivan Labanca ◽  
Darryl Newborough ◽  
...  
Keyword(s):  
Linear Array ◽  
Imaging System ◽  
Single Photon ◽  
Photon Counting ◽  
Single Photon Detection ◽  
Photon Detection ◽  
Central Wavelength ◽  
Depth Imaging ◽  
Single Photon Counting ◽  
Avalanche Diode

We present an optical depth imaging system suitable for highly scattering underwater environments. The system used the time-correlated single-photon counting (TCSPC) technique and the time-of-flight approach to obtain depth profiles. The single-photon detection was provided by a linear array of single-photon avalanche diode (SPAD) detectors fabricated in a customized silicon fabrication technology for optimized efficiency, dark count rate, and jitter performance. The bi-static transceiver comprised a pulsed laser diode source with central wavelength 670 nm, a linear array of 16 × 1 Si-SPAD detectors, with a dedicated TCSPC acquisition module. Cylindrical lenses were used to collect the light scattered by the target and image it onto the sensor. These laboratory-based experiments demonstrated single-photon depth imaging at a range of 1.65 m in highly scattering conditions, equivalent up to 8.3 attenuation lengths between the system and the target, using average optical powers of up to 15 mW. The depth and spatial resolution of this sensor were investigated in different scattering conditions.

Characterization of a Single Photon Counting Imaging System by Transfer Function Analysis

2007 ◽  
Vol 54 (1) ◽  
pp. 245-251 ◽  
Author(s):  
M. G. Bisogni ◽  
C. Carpentieri ◽  
P. Delogu ◽  
M. E. Fantacci ◽  
M. Novelli ◽  
...  
Keyword(s):  
Transfer Function ◽  
Imaging System ◽  
Single Photon ◽  
Function Analysis ◽  
Photon Counting ◽  
Single Photon Counting ◽  
Transfer Function Analysis

Single Photon Counting X-Ray Imaging System Using a Micro Hole and Strip Plate

2008 ◽  
Vol 55 (4) ◽  
pp. 2341-2345 ◽  
Author(s):  
Hugo Natal da Luz ◽  
Carlos A. B. Oliveira ◽  
Carlos D. R. Azevedo ◽  
Jamil A. Mir ◽  
Rui de Oliveira ◽  
...  
Keyword(s):  
Imaging System ◽  
Single Photon ◽  
Photon Counting ◽  
Single Photon Counting ◽  
X Ray ◽  
X Ray Imaging ◽  
Micro Hole ◽  
Strip Plate

High-resolution high-efficiency X-ray imaging system based on the in-line Bragg magnifier and the Medipix detector

2012 ◽  
Vol 20 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Patrik Vagovič ◽  
Dušan Korytár ◽  
Angelica Cecilia ◽  
Elias Hamann ◽  
Libor Švéda ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
High Efficiency ◽  
Imaging System ◽  
Single Photon ◽  
Signal To Noise Ratio ◽  
Photon Counting ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging

The performance of a recently developed full-field X-ray micro-imaging system based on an in-line Bragg magnifier is reported. The system is composed of quasi-channel-cut crystals in combination with a Medipix single-photon-counting detector. A theoretical and experimental study of the imaging performance of the crystals–detector combination and a comparison with a standard indirect detector typically used in high-resolution X-ray imaging schemes are reported. The spatial resolution attained by our system is about 0.75 µm, limited only by the current magnification. Compared with an indirect detector system, this system features a better efficiency, signal-to-noise ratio and spatial resolution. The optimal working resolution range of this system is between ∼0.4 µm and 1 µm, filling the gap between transmission X-ray microscopes and indirect detectors. Applications for coherent full-field imaging of weakly absorbing samples are shown and discussed.

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