Complementary Metal Oxide Semiconductor Camera Research Articles

Simultaneous measurement of cloud microphysical parameters based on digital holographic interferometry

Investigation of cloud microphysical is of great significance in deepening the understanding of the radiation energy budget, water cycle process, and precipitation mechanism, and improving the scientificity and effectiveness of artificial precipitation. Especially under the action of turbulence, in addition to shear and inertia, the turbulence in the cloud will accelerate the collision of cloud droplets through vortex superposition. The above process will further complicate the cloud microphysical characters. At present, the methods of measuring cloud microphysical parameters based on light scattering, collision and imaging theories encounter bottlenecks: the inversion process needs to make the assumptions about cloud droplet spectrum and particle characteristics, the impact process will destroy particle characteristics, and the three-dimensional characteristics of cloud particles cannot be obtained. Because of its many advantages, such as fast, real-time, non-destructive, non-invasive, high-resolution, full-field optical measurement, etc., in-line digital holographic interferometry is considered as a new potential tool for the dynamical measurement of cloud microphysical property. In particular, the mutual interference between the particle image and twin image is small under far-field recording conditions. In this paper, the measurement method of the on-line digital holographic interferometry based on interference theory, combining optical information processing, depth of field compression, and gray gradient variance technology of fusion holograms, is investigated. This method, with a <i>z</i>-axis position accuracy of 0.01 mm and system resolution of 2 μm, is employed for simultaneously and finely detecting the cloud droplet spectrum, cloud particle diameter, and number concentration. In the experiment, the liquid droplet with a median diameter of 3.9 μm, produced by the ultrasonic atomizer, is used as an example of the cloud particle. The measurement results are consistent with realistic scenario. By using a high speed charge coupled device or complementary metal oxide semiconductor camera, this method can solve the technical bottleneck of three-dimensional fine characteristics of cloud particle in airborne measurement by using cloud droplet spectrometer. It can provide effective support for the research of liquid water in the cloud, entrainment, condensation, collision, and temporal and spatial evolution laws. In addition, it has reference significance for the study of particle dynamics. Simultaneously, this method provides a feasible solution for the measurement of cloud in land-based and airborne platforms.

Assessing MMA Welding Process Stability Using Machine Vision-Based Arc Features Tracking System.

Arc length is a crucial parameter of the manual metal arc (MMA) welding process, as it influences the arc voltage and the resulting welded joint. In the MMA method, the process’ stability is mainly controlled by the skills of a welder. According to that, giving the feedback about the arc length as well as the welding speed to the welder is a valuable property at the stage of weld training and in the production of welded elements. The proposed solution is based on the application of relatively cheap Complementary Metal Oxide Semiconductor (CMOS) cameras to track the welding electrode tip and to estimate the geometrical properties of welding arc. All measured parameters are varying during welding. To validate the results of image processing, arc voltage was measured as a reference value describing in some part the process stability.

Using an acoustic levitator to investigate the drying kinetics and solids forming process of individual droplets during spray drying

AbstractSpray drying is a widely used process to turn slurries into dry powders and is especially important for thermally-sensitive materials, that are often found in the food or pharmaceutical industry. However, detailed insight into the drying kinetics during spray drying is difficult to investigate due to the boundary conditions in a spray drying tower. As a result, there is a lack of important information on the drying process and subsequent solidification of individual droplets. In this context, an experimental setup for a droplet positioned in a stationary ultrasonic field of an acoustic levitator is designed to enable a non-contacting measurement of the drying kinetics and the subsequent solidification process. To generate a comparable situation like in a real spray drying process, the droplet is positioned in an airflow, where air temperature, humidity, and velocity can be adjusted over wide range. Using an infrared camera to measure the surface temperature and a Complementary Metal Oxide Semiconductor (CMOS) camera for object recognition, the droplet can be observed continuously and drying kinetics of the droplet can be determined from the measured surface temperature and decreasing droplet size. Result of a 10 wt.% aqueous micro particle TiO2 suspension are reported and show that the investigated method is a very valuable and fast tool to safely scale-up spray drying systems very close to real process conditions. Especially when only small sample amounts are available in an early development stage.

Identification of low energy nuclear recoils in a gas time projection chamber with optical readout

The search for a novel technology, which is able to detect and reconstruct nuclear recoil events in the keV energy range, has become increasingly important now that vast regions of high mass weakly-interacting-massive-particle–like dark matter candidates have been excluded. Gaseous time projection chambers (TPC) with optical readout are very promising candidates combining the complete event information provided by the TPC technique with the high sensitivity and granularity of the latest generation light sensors. A TPC with an amplification at the anode, obtained with gas electron multipliers (GEMs), was tested at the Laboratori Nazionali di Frascati. Photons and neutrons from radioactive sources were employed to induce recoiling nuclei and electrons with kinetic energy in the range 1–100 keV. A He-CF4 (60/40) gas mixture was used at atmospheric pressure and the light produced during the multiplication in the GEM channels was acquired by a high-position resolution and low-noise complementary metal-oxide semiconductor camera and a photomultiplier. A multi-stage pattern recognition algorithm based on an advanced clustering technique is presented here. A number of cluster-shaped observables are used to identify nuclear recoils induced by neutrons, which originated from a AmBe source against x-ray 55Fe photoelectrons. An efficiency of 18% to detect nuclear recoils with an energy of about 6 keV is reached, while suppressing 96% of the 55Fe photoelectrons, making this optical read-out gas TPC a very promising candidate for future investigations of ultra-rare events such as directional direct dark matter searches.

Detective quantum efficiency of intensified CMOS cameras for Cherenkov imaging in radiotherapy

In this study the metric of detective quantum efficiency (DQE) was applied to Cherenkov imaging systems for the first time, and results were compared for different detector hardware, gain levels and with imaging processing for noise suppression. Intensified complementary metal oxide semiconductor cameras using different image intensifier designs (Gen3 and Gen2+) were used to image Cherenkov emission from a tissue phantom in order to measure the modulation transfer function (MTF) and noise power spectrum (NPS) of the systems. These parameters were used to calculate the DQE for varying acquisition settings and image processing steps. MTF curves indicated that the Gen3 system had superior contrast transfer and spatial resolution than the Gen2+ system, with values of 0.52 mm−1 and 0.31 mm−1, respectively. With median filtering for noise suppression, these values decreased to 0.50 mm−1 and 0.26 mm−1. The maximum NPS values for the Gen3 and Gen2+ systems at high gain were 1.3 × 106 mm2 and 9.1 × 104 mm2 respectively, representing a 14x decrease in noise power for the Gen2+ system. Both systems exhibited increased NPS intensity with increasing gain, while median filtering lowered the NPS. The DQE of each system increased with increasing gain, and at the maximum gain levels the Gen3 system had a low-frequency DQE of 0.31%, while the Gen2+ system had a value of 1.44%. However, at a higher frequency of 0.4 mm−1, these values became 0.54% and 0.03%. Filtering improved DQE for the Gen3 system and reduced DQE for the Gen2+ system and had a mix of detrimental and beneficial qualitative effects by decreasing the spatial resolution and sharpness but also substantially lowering noise. This methodology for DQE measurement allowed for quantitative comparison between Cherenkov imaging cameras and improvements to their sensitivity, and yielded the first formal assessment of Cherenkov image formation efficiency.

A Novel Brachytherapy Endoscopic Tandem and Inflatable Ovoids Applicator for Cervical and Uterine Neoplasms

Brachytherapy using the Fletcher-Suit-Delclos (FSD) applicator is an effective treatment modality for cervical and uterine cancers. The traditional FSD applicator typically consists of 8-pieces that are assembled in the patient under anesthesia. The procedure can be lengthy due to difficulty visualizing the cervical os, poor applicator design and assembly difficulty. The purpose of this study is to build prototypes of a user-friendly applicator, which improve patient comfort and care while minimizing intravaginal manipulation and optimizing inter fractions reproducible geometry with superior dosimetric properties. 3D CAD software was used to create a model of an applicator and simulate its intended functionalities. A CT and MRI friendly prototype made of balloons and plastics manufactured based on the CAD model. The prototype device is comprised of two main pieces; an endoscopic tandem using a miniaturized Complementary Metal Oxide Semiconductor (CMOS) camera connected to a computer and two inflatable ovoids. The ovoids consist of a two inflatable balloon assembly that can be inserted simultaneously and attached to the already placed tandem, and be inflated with different volumes of water. Further, balloon retractors were designed to separate the bladder and the rectum from the implant plane. The prototype was assembled with CT and MRI scans acquired. Isodose lines for a 7Gy dose to point A were generated. Our preliminary tests found an easier and faster assembly of the endoscopic tandem and inflatable ovoids. All the minor adjustments to an ideal geometry can be done outside the patient similar to a laparoscopy procedure minimizing intravaginal manipulations. The endoscopic tandem easily visualizes the cervical os while prevents the perforations or injury to the uterus. The bladder and rectal balloons replacing the painful gauze packing and inflate to get a bladder and rectum displacement of >2cm from the plane of the implant sparing the organs at risk significantly. Our initial estimates indicate that our device will decrease the implant times significantly, reducing the time under anesthesia, while promoting patient safety, complication reduction, and lowering overall treatment cost. The applicator CT and MRI images confirmed applicator’s compatibilities with these imaging modalities. The endoscopic tandem improves cervical os visibility and overall tandem placement. Further, with up to 15% of the tandems causing uterine perforation, using the camera aids in preventing the injury and potential morbidities associated with it. We achieve significant improvement in sparing the bladder and the rectum while delivering the same dose as the conventional FSD device. A comparative implant and dosimetric studies in a phantom with the applicators currently in clinical use are warranted in future studies.

Modelization and Characterization of a CMOS Camera as an Optical Real-Time Oscilloscope

Complementary Metal-Oxide Semiconductor (CMOS) camera sensors are embedded in many consumer electronics products: thanks to the Rolling Shutter (RS) readout mode, they can detect a time-varying light intensity, which is the key to realize Optical Camera Communication (OCC). To this aim, we introduce here a model describing the camera as a Real-Time Oscilloscope (RTO) detecting optical signals; by means of this approach, we can now characterize the Complementary Metal-Oxide Semiconductor (CMOS) camera by means of parameters that correspond to common oscilloscope specifications, such as the frequency response, the noise, the Signal to Noise Ratio (SNR), the total harmonic distortion (THD), etc.; all of these are introduced and measured in terms of the camera parameters. This approach provides for the first time a set of quantitative tools that should be used to maximize the OCC transmission performance by allowing the optimal selection of the camera settings.

Experiment and simulation of the effects of non-uniform magnetic field on the regression rate of PMMA

Burning rate modulation of solid fuel can improve the performance of solid fuel ramjet over a wider altitude or Mach number envelopes. To better control the burning rate of a solid fuel, the effect of magnetic fields on the regression rate of solid fuel was experimentally and numerically investigated. In this experiment, the regression rates of polymethyl methacrylate (PMMA) rods under different types of magnetic field gradients were measured. Meanwhile, the morphological changes in the flame during combustion were recorded by a complementary metal-oxide semiconductor (CMOS) camera. The experimental results indicated that the regression rate for PMMA varies regularly with various magnetic field gradients, with rates in the range from -32.5% to 10.8%. Simultaneously, the flame structure also changes. The numerical simulation that considered both gas-phase combustion and gas-solid heat transfer produced results that were in good agreement with the experiment. The results show that the change in the regression rate is a result of the magnetic force acting on the paramagnetic and diamagnetic materials. By changing the flow field, the magnetic force can change the flame shape and temperature distribution. This alters the heat exchanged between the gas and the fuel surface and thus, changes the burning rate. It was found that the burning rate of solid fuel can be adjusted regularly by applying different types of non-uniform magnetic fields, and it may be used in the solid fuel ramjet burning rate modulation.

An Integrated Smartphone-Based Genetic Analyzer for Qualitative and Quantitative Pathogen Detection.

The use of the smartphone is an ideal platform to realize the future point-of-care (POC) diagnostic system. Herein, we propose an integrated smartphone-based genetic analyzer. It consists of a smartphone and an integrated genetic analysis unit (i-Gene), in which the power of the smartphone was utilized for heating the gene amplification reaction, and the camera function was used for imaging the colorimetric change of the reaction for quantitative and multiplex foodborne pathogens. The housing of i-Gene was fabricated by using a 3D printer, which was equipped with a macro lens, white LEDs, a disposable microfluidic chip for loop-mediated isothermal amplification (LAMP), a thin-film heater, and a power booster. The i-Gene was installed on the iPhone in alignment with a camera. The LAMP mixture for Eriochrome Black T (EBT) colorimetric detection was injected into the LAMP chip to identify Escherichia coli O157:H7, Salmonella typhimurium, and Vibrio parahaemolyticus. The proportional–integral–derivative controller-embedded film heater was powered by a 5.0 V power bank to maintain 63 °C for the LAMP reaction. When the LAMP proceeded, the color was changed from violet to blue, which was real-time monitored by the smartphone complementary metal oxide semiconductor camera. The images were transported to the desktop computer via Wi-Fi. The quantitative LAMP profiles were obtained by plotting the ratio of green/red intensity versus the reaction time. We could identify E. coli O157:H7 with a limit of detection of 101 copies/μL within 60 min. Our proposed smartphone-based genetic analyzer offers a portable, simple, rapid, and cost-effective POC platform for future diagnostic markets.

Experimental study of an initially pressurized water target irradiated by a proton beam

This experimental visualization study was conducted to investigate and define the phenomena of an initially pressurized liquid water target that can prevent the boiling of water when the target is irradiated with a 30-MeV proton beam produced using the MC-50 Cyclotron at Korea Institute of Radiological and Medical Sciences. At various initial pressures and proton beam currents, the behavior of the target water was investigated using a complementary metal–oxide–semiconductor camera. We confirmed that an appropriate initial pressure could indeed prevent local bulk boiling, and be determined by solving Rayleigh's equation and the Clausius–Clapeyron equation for homogeneous bubble growth using the measured bubble size generated at the Bragg-peak region. The saturation temperature of the initial pressure must be higher than the calculated local water temperature at the Bragg-peak region. The final pressure of the water target increased proportionally with the initial pressure and proton beam current. The penetration depth of the beam varied with beam current and slightly with the final pressure, as evidenced by the emission of blue light in all experimental cases.

Ultrabroadband and Low-Dispersion Multiple-Joint Transmission-Line for Terahertz Region

A multiple-joint transmission line based on the principle of the periscope was developed to realize the flexible guidance of terahertz (THz) waves. The transmission line has a slightly larger diameter than the standard plastic hollow-pipe waveguide, sufficient stability, low transmission loss, ultrabroadband spectrum, and low dispersion. The transmission line is evaluated using a THz time-domain spectrometer consisting of reflective two-dimensional electro-optic sampling with a high-speed complementary metal-oxide semiconductor camera.

Surface Defect Detection for Mobile Phone Back Glass Based on Symmetric Convolutional Neural Network Deep Learning

Defect detection based on machine vision and machine learning techniques has drawn much attention in recent years. Deep learning is very suitable for such segmentation and detection tasks and has become a promising research area. Surface quality inspection is essentially important in the manufacturing of mobile phone back glass (MPBG). Different types of defects are produced because of the imperfection of the manufacturing technique. Unlike general transparent glass, screen printing glass has totally different reflection and scattering characteristics, which means the traditional dark-field imaging system is not suitable for this task. Meanwhile, the imaging system requires high resolution since the minimum defect size can be 0.005 mm2. According to the imaging characteristics of screen printing glass, this paper proposes a coaxial bright-field (CBF) imaging system and low-angle bright-field (LABF) imaging system, and 8K line-scan complementary metal oxide semiconductor(CMOS) cameras are utilized to capture images with the resolution size of 16,000*8092. The CBF system is applied for the weak-scratch and discoloration defects while the LABF system is applied for the dent defect. A symmetric convolutional neural network composed of encoder and decoder structures is proposed based on U-net, which produces a semantic segmentation with the same size as the original input image. More than 10,000 original images were captured, and more than 30,000 defective and non-defective images were manually annotated in the glass surface defect dataset (GSDD). Verified by the experiments, the results showed that the average precision reaches more than 91% and the average recall rate reaches more than 95%. The method is very suitable for the surface defect inspection of screen printing mobile phone back glass.

Tissue Thickness Interferes With the Estimation of the Immunohistochemical Intensity: Introduction of a Control System for Managing Tissue Thickness.

The conversion of immunohistochemical (IHC) results from 3-dimensional tissue to a 2-dimensional visual image without considering tissue thickness poses a considerable risk of misleading IHC intensities. The present study aimed to clarify whether tissue thickness interferes with the estimation of IHC staining intensity and to introduce a control system to manage it. We prepared cell lines that are used as controls for human epidermal growth factor receptor 2 (HER2) IHC (MDA-MB-231, MDA-MB-175VII, MDA-MV-453, and SK-BR-3), a polyclonal antibody for HER2, an interferometry to measure the tissue thickness of formalin-fixed paraffin-embedded sections, a microscope with a Halogen or an LED light source, a complementary metal-oxide semiconductor camera in which the output signal can be corrected to γ=1, and a program to estimate color elements (hue, saturation, and luminance). It was examined whether tissue thickness interferes with the experimental scoring systems and practical classification of the routine HER2 scoring system. A noncellular control was shown to be better than a cellular control for managing tissue thickness. The IHC intensity for HER2 was correlated with tissue thickness (R2=0.8094), even under the less-standardized condition, but this correlation was better under the improved standardized condition using corrected γ=1 (R2=0.9282). Discrepancies in practical HER2 scores were increased in sections with thicknesses <2 and >5 μm. A control system to manage tissue thickness was introduced. Tissue thickness interferes with the estimation of the IHC intensity of HER2 in both experimental and practical scoring systems. A control system for managing tissue thickness is essential to increase the benefits of IHC as a standardized assay for clinical applications.

Layer-wise control of selective laser melting by means of inline melt pool area measurements

Industrial selective laser melting (SLM) systems commonly employ a fixed set of process parameters throughout the build of the same component. The process parameters are generally found by experimental studies carried out on simple geometries which achieve high density. A common issue is related to the fact that the single set of parameters can be inadequate for small sections and overhang regions where thermal accumulation can occur. An online adaptation of process parameters is required for avoiding such issues and defects that commonly arise, such as the swelling phenomenon. A real-time control strategy would be desirable. However, the real-time control requires fast acquisition and reaction in the order of microseconds. Another approach is to provide corrective actions in a layer-wise fashion by elaborating the monitoring data collected during the previous layer. Therefore, this work proposes a layer-wise control strategy based on coaxial melt pool monitoring. For this purpose, an open SLM platform is employed, fitted with a complementary metal-oxide semiconductor camera, to view the process emission in the near infrared region. Initially, the nominal level of the melt pool area is defined on a simple geometry. Then, the melt pool area is monitored on more complex shapes. The melt pool area measured on each scan vector of a given layer is used to compensate the energy density of the same scan vector at the next layer. The results show an effective reduction of swelling defects on small geometries with fine details.

Miniaturized Continuous-Flow Digital PCR for Clinical-Level Serum Sample Based on the 3D Microfluidics and CMOS Imaging Device.

In recent years, the development of polymerase chain reaction (PCR) technology has focused on digital PCR, which depends on the microfluidics. Based on continuous-flow microfluidic technology, this paper designed a miniaturized digital PCR amplification system, and greatly reduced the area required for microdroplet generation and reaction. The core rod. made of polydimethylsiloxane (PDMS), was combined with the Teflon tube to form 3D microfluidics, which requires only one heating source to form the temperature difference required for gene amplification. Only two 34 g needles can form and transmit micro-droplets in a 4-fold tapered Teflon tube, which is the simplest method to generate digital PCR droplets as far as we know, which allows the microdroplet generation device to be free from dependence on expensive chips. A complementary metal oxide semiconductor (CMOS) camera was used as a detection tool to obtain fluorescence video for the entire loop area or a specified loop area. In addition, we developed a homebrew for automatic image acquisition and processing to realize the function of digital PCR. This technique realizes the analysis of clinical serum samples of hepatitis B virus (HBV) and obtained the same results as real-time quantitative PCR. This system has greatly reduced the size and cost of the entire system, while maintaining a stable response.

Transcription Factors and DNA Play Hide and Seek.

Transcription factors (TFs) bind to specific DNA motifs to regulate the expression of target genes. To reach their binding sites, TFs diffuse in 3D and perform local motions such as 1D sliding, hopping, or intersegmental transfer. TF-DNA interactions depend on multiple parameters, such as the chromatin environment, TF partitioning into distinct subcellular regions, and cooperativity with other DNA-binding proteins. In this review, how current understanding of the search process has initially been shaped by prokaryotic studies is discussed, as well as what is known about the parameters regulating TF search efficiency in the context of the complex eukaryotic chromatin landscape.

An experimental study of stunned state detection for broiler chickens using an improved convolution neural network algorithm

Effective recognition method of broiler stunned state has always been an important issue in real industries. In recent years, recognition methods such as neural networks have been receiving increasing attention due to their great merits of high diagnostic accuracy and easy implementation. To improve the accuracy and efficiency of broiler stunned state recognition, an improved fast region-based convolutional neural network (You Only Look Once + Multilayer Residual Module (YOLO + MRM)) algorithm was proposed and applied to the recognition of three broiler stunned states: insufficient, appropriate and excessive stuns. The images were collected from a broiler-slaughtering line using a complementary metal-oxide semiconductor (CMOS) camera. The area of the head and wings of a broiler in the original image was marked according to the PASCAL VOC data format and the dataset of each broiler stunned state was obtained. The results showed that the YOLO + MRM algorithm achieved good performance with an accuracy of 96.77%. To compare YOLO + MRM with other models, similar experiments were conducted using a conventional back propagation neural network (BP-NN) classifier, as well as YOLO, and the recognition accuracies were 90.11% and 94.74%, respectively. YOLO + MRM can complete the detection task of more than 180,000 broilers per hour. Compared with the traditional method, little prior expertise on image recognition is required, the recognition accuracy and speed are improved obviously. This study has provided a foundation and highlighted the potential for automatically detecting the stunned state of broiler chickens, which is crucial for the success of an automatic electric stunning process in the poultry industry.

High-resolution imaging of organic pharmaceutical crystals by transmission electron microscopy and scanning moiré fringes.

SummaryFormulation processing of organic crystalline compounds can have a significant effect on drug properties, such as dissolution rate or tablet strength/hardness. Transmission electron microscopy (TEM) has the potential to resolve the atomic lattice of these crystalline compounds and, for example, identify the defect density on a particular crystal face, provided that the sensitivity of these crystals to irradiation by high‐energy electrons can be overcome. Here, we acquire high‐resolution (HR) lattice images of the compound furosemide using two different methods: low‐dose HRTEM and bright‐field (BF) scanning TEM (STEM) scanning moiré fringes (SMFs). Before acquiring HRTEM images of furosemide, a model system of crocidolite (asbestos) was used to determine the electron flux/fluence limits of low‐dose HR imaging for our scintillator‐based, complementary metal‐oxide semiconductor (CMOS) electron camera by testing a variety of electron flux and total electron fluence regimes. An electron flux of 10 e−/(Å2 s) and total fluence of 10 e−/Å2 was shown to provide sufficient contrast and signal‐to‐noise ratio to resolve 0.30 nm lattice spacings in crocidolite at 300 kV. These parameters were then used to image furosemide which has a critical electron fluence for damage of ≥10 e−/Å2 at 300 kV. The resulting HRTEM image of a furosemide crystal shows only a small portion of the total crystal exhibiting lattice fringes, likely due to irradiation damage during acquisition close to the compound's critical fluence. BF‐STEM SMF images of furosemide were acquired at a lower electron fluence (1.8 e−/Å2), while still indirectly resolving HR details of the (001) lattice. Several different SMFs were observed with minor variations in the size and angle, suggesting strain due to defects within the crystal. Overall BF‐STEM SMFs appear to be more useful than BF‐STEM or HRTEM (with a CMOS camera) for imaging the crystal lattice of very beam‐sensitive materials since a lower electron fluence is required to reveal the lattice. BF‐STEM SMFs may thus prove useful in improving the understanding of crystallization pathways in organic compounds, degradation in pharmaceutical formulations and the effect of defects on the dissolution rate of different crystal faces. Further work is, however, required to quantitatively determine properties such as the defect density or the amount of relative strain from a BF‐STEM SMF image.

CMOS camera based visible light communication (VLC) using grayscale value distribution and machine learning algorithm.

We demonstrate a visible light communication (VLC) system using light emitting diode (LED) backlight display panel and mobile-phone complementary-metal-oxide-semiconductor (CMOS) camera. The panel is primarily used for displaying advertisements. By modulating its backlight, dynamic contents (i.e. secondary information) can be transmitted wirelessly to users based on rolling shutter effect (RSE) of the CMOS camera. As different display content will be displayed on the panel, the VLC performance is significantly limited if the noise-ratio (NR) is too high. Here, we propose and demonstrate a CMOS RSE pattern demodulation scheme using grayscale value distribution (GVD) and machine learning algorithm (MLA) to significantly enhance the demodulation.

Nuclear radiation detection based on uncovered CMOS camera under dynamic scene

Nuclear technology is being promoted and applied worldwide but poses a certain threat to public safety, thus necessitating nuclear radiation detection. In addition to the use of dedicated instruments, the use of surveillance cameras with complementary metal oxide semiconductor (CMOS) sensors is a promising direction for nuclear radiation detection. Currently, such use requires masking the camera lens or working under a static environment, conditions under which a camera cannot perform surveillance monitoring. In this article, we propose a method for detecting nuclear radiation based on an uncovered CMOS camera that enables nuclear radiation detection while the camera is in surveillance monitoring mode. First, we captured videos without covering the camera lens of irradiation from a 99mTc radioactive source. Then, an inter-frame difference algorithm and Gaussian smoothing method were used to reduce the interference of moving objects and visible light on the images. Finally, a series of thresholds were selected to test the validity of our detection method on a validation set. The experimental results indicate that the proposed method can effectively detect nuclear radiation. It is further verified that the surveillance camera can perform surveillance monitoring and radiation detection simultaneously.