Showing papers on "Night vision published in 2018"

Atomically thin noble metal dichalcogenide: a broadband mid-infrared semiconductor.

Abstract: The interest in mid-infrared technologies surrounds plenty of important optoelectronic applications ranging from optical communications, biomedical imaging to night vision cameras, and so on. Although narrow bandgap semiconductors, such as Mercury Cadmium Telluride and Indium Antimonide, and quantum superlattices based on inter-subband transitions in wide bandgap semiconductors, have been employed for mid-infrared applications, it remains a daunting challenge to search for other materials that possess suitable bandgaps in this wavelength range. Here, we demonstrate experimentally for the first time that two-dimensional (2D) atomically thin PtSe2 has a variable bandgap in the mid-infrared via layer and defect engineering. Here, we show that bilayer PtSe2 combined with defects modulation possesses strong light absorption in the mid-infrared region, and we realize a mid-infrared photoconductive detector operating in a broadband mid-infrared range. Our results pave the way for atomically thin 2D noble metal dichalcogenides to be employed in high-performance mid-infrared optoelectronic devices.

Ultra-thin high-efficiency mid-infrared transmissive Huygens meta-optics

Abstract: The mid-infrared (mid-IR) is a strategically important band for numerous applications ranging from night vision to biochemical sensing. Here we theoretically analyzed and experimentally realized a Huygens metasurface platform capable of fulfilling a diverse cross-section of optical functions in the mid-IR. The meta-optical elements were constructed using high-index chalcogenide films deposited on fluoride substrates: the choices of wide-band transparent materials allow the design to be scaled across a broad infrared spectrum. Capitalizing on a two-component Huygens’ meta-atom design, the meta-optical devices feature an ultra-thin profile (λ0/8 in thickness) and measured optical efficiencies up to 75% in transmissive mode for linearly polarized light, representing major improvements over state-of-the-art. We have also demonstrated mid-IR transmissive meta-lenses with diffraction-limited focusing and imaging performance. The projected size, weight and power advantages, coupled with the manufacturing scalability leveraging standard microfabrication technologies, make the Huygens meta-optical devices promising for next-generation mid-IR system applications. Mid-IR optics can require exotic materials or complicated processing, which can result in high cost and inferior quality. Here the authors report the demonstration of high-efficiency mid-IR transmissive lenses based on dielectric Huygens metasurface, showing diffraction limited focusing and imaging performance.

Panretinal Photocoagulation: A Review of Complications.

Abstract: Panretinal photocoagulation (PRP) is a mainstay of therapy for retinal ischemic disease. The procedure involves creating thermal burns in the peripheral retina leading to tissue coagulation, the overall consequence of which is improved retinal oxygenation. While highly effective, there have been concerns historically regarding the anatomic effects and visual complications following PRP, the most common of which include choroidal effusions, exudative retinal detachments, macular edema, visual field deficits, and night vision defects. The occurrence of these complications is closely tied to laser parameters such as increased duration and power and intensive treatment in a single sitting, all of which cause increased dispersion of thermal energy within the retina and choroid. The advent of newer laser delivery systems, such as the multispot pattern laser, has greatly mitigated but not eliminated these issues. The following article reviews the most common complications following PRP treatment, including reported occurrences, inciting factors, and underlying pathophysiology.

Image processing method and device

Abstract: The embodiment of the invention discloses an image processing method and device. A single-pixel imaging principle is utilized, a nonlinear mathematical model is adopted, and a small number of photonsare subjected to mathematical light supplement and then are imaged through a physical mechanism. The method includes: obtaining a digital image of an original real scene image; formatting and refroming the digital image; mapping the value domain of the pixel value of the digital image to [0, 1], carrying out light supplementing transformation on the digital image subjected to formatting and reforming by adopting a first nonlinear mathematical model; and mapping single-photon imaging to multi-photon imaging, carrying out contrast auxiliary transformation on the digital image subjected to lightsupplement transformation by using a second nonlinear mathematical model, and outputting the digital image subjected to formatting transformation, light supplement transformation and contrast auxiliary transformation. Based on a single-pixel imaging principle and a physical mechanism of imaging of a small number of photons after mathematical light supplement, the purpose of night vision or enhancement of the night vision effect in the prior art is achieved.

Origin of the green persistent luminescence of Eu-doped SrAl2O4 from a multiconfigurational ab initio study of 4f7 → 4f65d1 transitions

Abstract: The green persistent luminescence of Eu2+ in SrAl2O4 has been widely applied in self-sustained night vision due to its long duration and ability to be excited by sunlight. However, the question of which substitutional site in the lattice is responsible for the green emission remains unresolved. Herein, we perform multiconfigurational ab initio calculations at the CASSCF/CASPT2 level with the spin–orbit effect on 4f7 → 4f65d1 (4f → 5d) transitions of Eu2+ located at the Sr1 and Sr2 sites of SrAl2O4. By comparison of the calculated transition energies with data from experimental low-temperature excitation spectra, the green luminescence is unambiguously assigned to Eu2+ at the Sr2 site. In addition, by using the present results as a calibration, the accuracies of the literature-reported DFT-based approaches to the Eu2+ 4f → 5d transition energies are discussed. This investigation is expected to motivate more exploration of multiconfigurational ab initio methodology to elucidate luminescence properties of Eu2+-activated complex phosphors.

Smart Home Anti-Theft System: A Novel Approach for Near Real-Time Monitoring and Smart Home Security for Wellness Protocol

Abstract: The proposed research methodology aims to design a generally implementable framework for providing a house owner/member with the immediate notification of an ongoing theft (unauthorized access to their premises). For this purpose, a rigorous analysis of existing systems was undertaken to identify research gaps. The problems found with existing systems were that they can only identify the intruder after the theft, or cannot distinguish between human and non-human objects. Wireless Sensors Networks (WSNs) combined with the use of Internet of Things (IoT) and Cognitive Internet of Things are expanding smart home concepts and solutions, and their applications. The present research proposes a novel smart home anti-theft system that can detect an intruder, even if they have partially/fully hidden their face using clothing, leather, fiber, or plastic materials. The proposed system can also detect an intruder in the dark using a CCTV camera without night vision capability. The fundamental idea was to design a cost-effective and efficient system for an individual to be able to detect any kind of theft in real-time and provide instant notification of the theft to the house owner. The system also promises to implement home security with large video data handling in real-time. The investigation results validate the success of the proposed system. The system accuracy has been enhanced to 97.01%, 84.13, 78.19%, and 66.5%, in scenarios where a detected intruder had not hidden his/her face, hidden his/her face partially, fully, and was detected in the dark from 85%, 64.13%, 56.70%, and 44.01%.

High-performance GeSn photodetector and fin field-effect transistor (FinFET) on an advanced GeSn-on-insulator platform.

Abstract: We report the first demonstration of high-performance GeSn metal-semiconductor-metal (MSM) photodetector and GeSn p-type fin field-effect transistor (pFinFET) on an advanced GeSn-on-insulator (GeSnOI) platform by complementary metal-oxide-semiconductor (CMOS) compatible processes. The detection range of GeSn photodetector is extended beyond 2 µm, with responsivities of 0.39 and 0.10 A/W at 1550 nm and 2003 nm, respectively. Through the insertion of an ultrathin Al2O3 Schottky-barrier-enhancement layer, the dark current IDark of the GeSn photodetector is suppressed by more than 2 orders of magnitude. An impressive IDark of ~65 nA was achieved at an operating voltage of 1.0 V. A frequency response measurement reveals the achievement of a 3-dB bandwidth of ~1.4 GHz at an illumination wavelength of 2 µm. GeSn pFinFET with fin width (Wfin) scaled down to 15 nm was also fabricated on the GeSnOI platform, exhibiting a small subthreshold swing (S) of 93 mV/decade, a high drive current of 176 µA/µm, and good control of short channel effects (SCEs). This work paves the way for realizing compact, low-cost, and multi-functional GeSn-on-insulator opto-electronic integrated circuits.

Association of Low Luminance Questionnaire With Objective Functional Measures in Early and Intermediate Age-Related Macular Degeneration

Abstract: Purpose To determine whether Low Luminance Questionnaire (LLQ) scores are associated with objective measures of visual function in early and intermediate age-related macular degeneration (AMD). Methods Cross-sectional study of subjects with early AMD Age-Related Eye Disease Study (AREDS) stage 2, N = 33), intermediate AMD (AREDS stage 3, N = 47), and age-matched healthy controls (N = 21). Subjects were interviewed with the LLQ. Psychophysical tests performed included best-corrected visual acuity (BCVA), mesopic microperimetry, dark adaptometry (DA), low luminance visual acuity (LLVA), and cone contrast test (CCT). Low luminance deficit (LLD) was the difference in the number of letters read under photopic versus low luminance settings. The relationship between LLQ and visual function test scores was assessed with linear regression. Results Subjects with intermediate AMD had significantly lower LLQ composite scores (mean = 75.8 ± 16.7; median = 76, range [29, 97]) compared with early AMD (mean = 85.3 ± 13.3; median = 88, range [50, 100], P = 0.007) or controls (mean = 91.4 ± 6.5; median = 94, range [79, 99], P < 0.001) in the overall cohort. LLQ composite scores were associated with computerized BCVA (β = 0.516), computerized LLVA at two background luminance (1.3 cd/m2, β = 0.660; 0.5 cd/m2, β = 0.489) along with their respective computerized LLDs (β = -0.531 and -0.467), rod intercept (β = -0.312), and CCT green (β = 0.183) (all P < 0.05). Only the computerized LLVAs and computerized LLDs remained statistically significant after adjusting for AMD versus control status (P < 0.05). Among AMD subjects, LLQ composite scores were significantly associated with the computerized LLVAs (β = 0.622 and 0.441) and LLDs (β = -0.795 and -0.477) at both the 1.3 and 0.5 cd/m2 luminance levels, respectively, and these associations remained significant after adjusting for AMD severity (P < 0.05). Conclusions Among subjects with early and intermediate AMD, LLQ scores were significantly associated with computerized LLVA and LLD. LLQ is a useful patient-centered functional measure of visual impairment in early and intermediate AMD.

Photon-limited face image super-resolution based on deep learning

Abstract: With one single photon camera (SPC), imaging under ultra weak-lighting conditions may have wide-ranging applications ranging from remote sensing to night vision, but it may seriously suffer from the problem of under-sampled inherent in SPC detection. Some approaches have been proposed to solve the under-sampled problem by detecting the objects many times to generate high-resolution images and performing noise reduction to suppress the Poission noise inherent in low-flux operation. To address the under-sampled problem more effectively, a new approach is developed in this paper to reconstruct high-resolution images with lower-noise by seamlessly integrating low-light-level imaging with deep learning. In our new approach, all the objects are detected only once by SPC, where a deep network is learned to reduce noise and reconstruct high-resolution images from the detected noisy under-sampled images. In order to demonstrate our proposal is feasible, we first select a special category to verify by experiment, which are human faces. Such deep network is able to recover high-resolution and lower-noise face images from new noisy under-sampled face images and the resolution can achieve 4× up-scaling factor. Our experimental results have demonstrated that our proposed method can generate high-quality images from only ~0.2 detected signal photon per pixel.

Infrared Thermography and its Applications: A Review

Abstract: Thermal imaging camera is a device which is used to detect infrared radiations emitted from an object to give a thermal profile of the scene. This device was initially used for surveillance purpose and as night vision camera. With the advancement in technology, there are significant additions to camera capabilities and prices has decreased. Therefore, infrared thermography (IRT) has grown to become very popular and widely accepted tool as it enables temperature measurement in real time. IRT is very convenient, fast, reliable, non-contact and cost-effective method which can be practiced for condition monitoring as well as for preventive and predictive maintenance in different areas such as electrical stations, buildings surveys, mechanical components and equipments. This survey presents a review of the advancement in IRT cameras and its applications in various fields. The basics of IRT and thermal radiation are discussed in details.

Spatial and Frequency Selective Plasmonic Metasurface for Long Wavelength Infrared Spectral Region

Abstract: The development of novel approaches that control absorption and emission operating in the long wavelength infrared (LWIR) spectral region is of fundamental importance for many applications, such as remote temperature sensing, thermal imaging, radiation cooling, environmental monitoring, and night vision. A high performance plasmonic metasurface–based absorber for the LWIR spectral region is presented. In the design, a pyroelectric thin film, poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer, is introduced as spacer, that offers the device not only multiple selective high absorption bands but also promising potential for application in optoelectronics. The angle-resolved optical responses show that the absorption effect is sensitive to the incident angles and can be controlled by the periodicity, indicating that the design can function as optical devices with directional and frequency-selective absorption/emission characteristics. By employing near-field optical microscopy, both the near-field amplitude and phase optical responses of the absorber are investigated at resonant wavelength, thereby providing direct experimental evidence to verify the nature of the absorption effect. To further demonstrate the versatility of the design, a particular metasurface patterned by the building blocks of the absorber is fabricated. 2D hyperspectral images show that such a patterned structure exhibits both frequency and spatially selective absorption.

Strain out a gnat and swallow a camel? - vision and driving in the Nordic countries.

Abstract: Purpose This study describes the present legislation for visual requirements for driving in the Nordic countries in relation to the European Driving License Directive. Methods Information about the formal legislation was gathered from each countries legal text. Further information about the implementation and common practices were achieved from national authorities in vision and driving. Results Even though the Nordic countries use the same framework of legislation, the implementation varies widely. Sweden and Norway have more specified visual field requirements than the others. On the other hand, no periodic testing of visual acuity (VA) is performed in Sweden as in all other Nordic countries. Physicians on Iceland are not obliged to report a person no longer fulfilling the visual requirements, as in other Nordic countries. In Denmark, Finland and Norway a person may apply for dispensation from the requirements by performing a practical driving test. In Sweden, a person applying for dispensation can undergo a traffic simulator test. Conclusion Because of the national legislation in the Nordic countries, a person with a visual impairment may be given different permissions depending on which country they live in. As the inhabitants in the Nordic countries frequently cross the regional borders, a harmonization of the legislation would be of value. More research in this field could provide future standards, combining the greatest autonomy with the highest possible safety.

Mid-wave and Long-Wave Infrared Linear Dichroism in a Hexagonal Perovskite Chalcogenide

Abstract: Mid-wave infrared (IR) and long-wave IR spectral ranges are of growing interest in various applications such as thermal imaging, thermography-based remote sensing, and night vision. Materials widely used for IR photodetectors in this regime include cadmium mercury telluride alloys and nanostructures of compound semiconductor. The materials development for IR optics will drive down the cost of IR optical systems and enable larger scale deployment. Here, we report a mid-wave IR responsive material composed of earth abundant and non-toxic elements, Sr1+xTiS3. It has a highly anisotropic quasi-one-dimensional structure similar to hexagonal perovskites. We grew large, high quality single crystals and studied its anisotropic optical properties. We observed two distinct optical absorption edges at ~2.5 um and ~5 um, respectively, for linear polarizations along two principal axes. The material demonstrated strong and broadband linear dichroism spanning mid-wave IR and long-wave IR, with a dichroitic ratio of up to 22.

Functional metabolite assemblies-a review.

Abstract: Metabolites are essential for the normal operation of cells and fulfill various physiological functions. It was recently found that in several metabolic disorders, the associated metabolites could self-assemble to generate amyloid-like structures, similar to canonical protein amyloids that have a role in neurodegenerative disorders. Yet, assemblies with typical amyloid characteristics are also known to have physiological function. In addition, many non-natural proteins and peptides presenting amyloidal properties have been used for the fabrication of functional nanomaterials. Similarly, functional metabolite assemblies are also found in nature, demonstrating various physiological roles. A notable example is the structural color formed by guanine crystals or fluorescent crystals in feline eyes responsible for enhanced night vision. Moreover, some metabolites have been used for the in vitro fabrication of functional materials, such as glycine crystals presenting remarkable piezoelectric properties or indigo films used to assemble organic semiconductive electronic devices. Therefore, we believe that the study of metabolite assemblies is not only important in order to understand their role in normal physiology and in pathology, but also paves a new route in exploring the fabrication of organic, bio-compatible materials.

A comparative analysis of rod bipolar cell transcriptomes identifies novel genes implicated in night vision

Abstract: In the mammalian retina, rods and a specialised rod-driven signalling pathway mediate visual responses under scotopic (dim light) conditions. As rods primarily signal to rod bipolar cells (RBCs) under scoptic conditions, disorders that affect rod or RBC function are often associated with impaired night vision. To identify novel genes expressed by RBCs and, therefore, likely to be involved in night vision, we took advantage of the adult Bhlhe23-/- mouse retina (that lacks RBCs) to derive the RBC transcriptome. We found that genes expressed by adult RBCs are mainly involved in synaptic structure and signalling, whereas genes that influence RBC development are also involved in the cell cycle and transcription/translation. By comparing our data with other published retinal and bipolar cell transcriptomes (where we identify RBCs by the presence of Prkca and/or Pcp2 transcripts), we have derived a consensus for the adult RBC transcriptome. These findings ought to facilitate further research into physiological mechanisms underlying mammalian night vision as well as proposing candidate genes for patients with inherited causes of night blindness.

Incidence and Outcomes of Optical Zone Enlargement and Recentration After Previous Myopic LASIK by Topography-Guided Custom Ablation.

Abstract: Purpose To report the incidence, visual and refractive outcomes, optical zone enlargement, and recentration using topography-guided CRS-Master TOSCA II software with the MEL 80 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) after primary myopic laser refractive surgery. Methods Retrospective analysis of 73 eyes (40 patients) with complaints of night vision disturbances due to either a decentration or small optical zone following a primary myopic laser refractive surgery procedure using the MEL 80 laser. Multiple ATLAS topography scans were imported into the CRS-Master software for topography-guided ablation planning. The topography-guided re-treatment procedure was performed as either a LASIK flap lift, a new LASIK flap, a side cut only, or photorefractive keratectomy. Axial curvature maps were analyzed using a fixed grid and set of concentric circles superimposed to measure the topographic optical zone diameter and centration. Follow-up was 12 months. Results The incidence of use in the population of myopic treatments during the study period was 0.79% (73 of 9,249). The optical zone diameter was increased by 11% from a mean of 5.65 to 6.32 mm, with a maximum change of 2 mm in one case. Topographic decentration was reduced by 64% from a mean of 0.58 to 0.21 mm. There was a 44% reduction in spherical aberration, 53% reduction in coma, and 39% reduction in total higher order aberrations. A subjective improvement in night vision symptoms was reported by 93%. Regarding efficacy, 82% of eyes reached 20/20 and 100% reached 20/32 (preoperative CDVA was 20/20 or better in 90%). Regarding safety, no eyes lost two lines of CDVA and 27% gained one line. Regarding predictability, 71% of re-treatments were within ±0.50 diopters. Conclusions Topography-guided ablation was effective in enlarging the optical zone, recentering the optical zone, and reducing higher order aberrations. Topography-guided custom ablation appears to be an effective method for re-treatment procedures of symptomatic patients after myopic LASIK. [J Refract Surg. 2018;34(2):121-130.].

Prospective Randomized Multicenter Comparison of the Clinical Outcomes of V4c and V5 Implantable Collamer Lenses: A Contralateral Eye Study

Abstract: Purpose To compare the visual and refractive outcomes and night vision performance questionnaire results between V4c and V5 implantable Collamer lenses in a prospective, randomized, multicenter study Settings Four refractive surgery centers Design Prospective randomized multicenter single-masked comparative study Methods Twenty-three patients were enrolled in this study A conventional V4c model (EVO Visian ICL) was implanted in one eye, and a V5 model (EVO+ Visian ICL), which has a larger optic diameter than the V4c model, was implanted in the contralateral eye The uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were evaluated before and 6 months after surgery At 6 months after surgery, a questionnaire on night vision disturbances was administered The efficacy, safety, and predictability of the two implanted ICL models were compared Results There were no significant differences in the postoperative UDVA and CDVA between the two ICL models The mean efficacy indexes for the V4c and V5 lenses were 116 ± 022 and 103 ± 023, respectively The mean safety indexes of the V4c and V5 lenses were 121 ± 020 and 119 ± 020, respectively The night vision performance questionnaire revealed that 7 patients (37%) noticed a difference in visual performance between the eyes, and all of them reported that they could see better at night with the V5-implanted eye compared with the V4c-implanted eye Conclusion The V4c and V5 ICL models achieved similar visual and refractive outcomes, whereas the V5 model showed a possible advantage in reducing night vision disturbances

Embedded computer vision detection fatigue driving method and device

Abstract: The invention discloses an embedded computer vision detection fatigue driving method. The method includes shooting a head picture of a driver, and carrying out face recognition and tracking; carryingout key point positioning, recording the feature points of eyes and mouth, and converting the feature points into a two-dimensional array, calculating the aspect ratio of the eyes and the mouth through a formula; according to the characteristics of different drivers' eyes, setting an aspect ratio threshold value of the eyes and the mouth, the frame aspect ratio threshold value of blinking generated by the condition that the continuous length-to-width ratio is smaller than the threshold value, and the frames of yawning generated by the condition that the continuous length-to-width ratio is greater than the threshold value; comparing the blinking times in a certain period with a normal standard value, and combining the yawning times, determining whether the driver is in the fatigue state, ifyes, starting a voice alarm device to carry out the voice prompt. The infrared night vision camera is adopted, and a picture can be shot clearly at night. The method is simple in step, high in operability, simple in device, convenient to install and carry and capable of realizing good fatigue driving detection.

Contrast enhancement of infrared images using Adaptive Histogram Equalization (AHE) with Contrast Limited Adaptive Histogram Equalization (CLAHE)

Abstract: The objective of this paper is to improve the general quality of infrared images by proposes an algorithm relying upon strategy for infrared images (IR) enhancement. This algorithm was based on two methods: adaptive histogram equalization (AHE) and Contrast Limited Adaptive Histogram Equalization (CLAHE). The contribution of this paper is on how well contrast enhancement improvement procedures proposed for infrared images, and to propose a strategy that may be most appropriate for consolidation into commercial infrared imaging applications.The database for this paper consists of night vision infrared images were taken by Zenmuse camera (FLIR Systems, Inc) attached on MATRIC100 drone in Karbala city. The experimental tests showed significant improvements.

Elastic‐viscoplasticity modeling of the thermo‐mechanical behavior of chalcogenide glass for aspheric lens molding

Abstract: Chalcogenide glass (ChG), as an alternative material in place of single-crystal germanium, is increasingly used in thermal imaging, night vision, and infrared guidance systems, etc., owing to their excellent formability through precision glass molding (PGM). The deformation mechanisms of these glasses at the molding temperature involve elasticity, plasticity, and viscous flow, which call for a new theoretical model to assist the design of PGM process. This paper investigates the thermo-mechanical properties of Ge22Se58As20 at the temperature above its softening point and establishes a new elastic-viscoplasticity model to describe its thermo-mechanical behaviors. After determining the model parameters through cylindrical compression tests, the new constitutive model is implemented in finite element method (FEM) of PGM to form an aspheric ChG lens. And the agreement of displacement-time curves between experimental and simulation results exhibit the validity of the proposed elastic-viscoplastic constitutive model.

Fusion of the low-light-level visible and infrared images for night-vision context enhancement

Abstract: For better night-vision applications using the low-light-level visible and infrared imaging, a fusion framework for night-vision context enhancement (FNCE) method is proposed. An adaptive brightness stretching method is first proposed for enhancing the visible image. Then, a hybrid multi-scale decomposition with edge-preserving filtering is proposed to decompose the source images. Finally, the fused result is obtained via a combination of the decomposed images in three different rules. Experimental results demonstrate that the FNCE method has better performance on the details (edges), the contrast, the sharpness, and the human visual perception. Therefore, better results for the night-vision context enhancement can be achieved.

IR and Visible Video Fusion for Surveillance

Abstract: Infrared (IR) imagery offers a promising alternative to visible imagery and is extensively used in military, surveillance and other applications. IR, however, has limitations of not detecting thermal variations after heavy rains when the temperature of the surrounding becomes uniform with the object of interest. Due to this fact, the relevant information from visible and IR videos are combined into one fused video. This paper aims to develop an efficient algorithm in order to fuse videos captured using infrared and visible cameras using different types of transforms and evaluate its performance measures. Tracking of single or multiple objects/people from the fused result has been further undertaken specifically for night vision using Background Subtraction[BS] and Kalman filtering.

Surveillance System for Detection of Suspicious Human Activities at War Field

Abstract: War field surveillance system plays vital role in security of every Nation. Major problems related are surveillance at national borders. Manual monitoring is relatively difficult in case of the borders where the area is too big; specifically, during night the majority of the attacks are executed by rivals where the human vision is not capable to identify enemy location. Therefor intelligent system needs to be developed which will automatically identify survival of enemy in less light situation or night. We put forward intelligent war field surveillance system consist of raspberry pi processor interfaced with night vision camera capable of sensing environment, intelligent decision making, commanding capability and performing action on the environment. The Internet of things is used to inform concern authority about enemy status. This system includes night vision camera and raspberry pi module which can transmit videos of the war field sequentially to prevent any hurt and loss to human life. The system will be used as proper machine for the defence sector to decrease the loss of human life and also useful to decrease infiltrations at border regions. It works on the principle of optical flow algorithm for movement detection. The developed algorithm is implemented in real time by motion based moving object detection method.

Acceleration of HOG based pedestrian detection in FIR camera video stream

Abstract: Pedestrian detection is one the main problem for the automotive applications which is a challenging task to do. In recent years, the number of approaches was developed to speed up the detection rate and accuracy. However, the general problem of detectors remains. The aim of the paper was to evaluate experimentally current and efficient pedestrian detection methods in night vision applications and propose some modifications to accelerate the image analysis workflow. In this paper, for night vision application we used an FIR domain camera. The novelty of the proposed solution lays in the application of HOG based pedestrian detector for FIR domain camera. An acceleration of the algorithm was achieved using subtraction of the thermally active regions before supplying these regions to the pre-trained feature descriptor. An experimental investigation has shown the significant improvement in pedestrian detection speed using solution, proposed in this paper. Our study shows that state of the art detectors can gain nearly triple initial detection rate using the same image data.

Automatic description method of night vision image based on deep convolutional-recurrent neural network

Abstract: The invention relates to an automatic description method of a night vision image based on a deep convolutional-recurrent neural network. The automatic description method is characterized by comprisingthe steps of: step 1, constructing a night vision image dataset; step 2, performing mirror symmetry processing on an original sample image; step 3, constructing the deep convolutional-recurrent neural network; step 4, and acquiring an image to be processed in real time, inputting the image into a deep convolutional neural network to obtain a corresponding characteristic pattern, inputting the obtained characteristic pattern into a deep recurrent neural network, and selecting words with the greatest probabilities to form a descriptive sentence of the image. The automatic description method obviously enhances the scene perceptibility of the night-vision image, improves the efficiency of understanding the image and reduces the complexity of manual operation.

Development of Marker-Free Night-Vision Displacement Sensor System by Using Image Convex Hull Optimization.

Abstract: Vision-based displacement sensors (VDSs) have the potential to be widely used in the structural health monitoring field, because the VDSs are generally easier to install and have higher applicability to the existing structures compared to the other conventional displacement sensors. However, the VDS also has disadvantages, in that ancillary markers are needed for extracting displacement data and data reliability is significantly lowered at night. In this study, a night vision displacement sensor (NVDS) was proposed to overcome the aforementioned two limitations. First, a non-contact NVDS system is developed with the installation of the infrared (IR) pass filter. Since it utilizes the wavelength of the infrared region and it is not sensitive to the change of a visible ray, it can precisely extract the shape information of the structure even at night. Second, a technique to extract the feature points from the images without any ancillary marker was formulated through an image convex hull optimization. Finally, the experimental tests of a three-story scaled model were performed to investigate the effectiveness of proposed NVDS at night. The results demonstrate that the NVDS has sufficiently high accuracy even at night and it can precisely measure the dynamic characteristics such as mode shapes and natural frequencies of the structure. The proposed system and formulation would extend the applicability of vision sensor not only into night-time measure but also marker-free measure.

Rapid Adaptation of Night Vision.

Abstract: Apart from the well-known loss of color vision and of foveal acuity that characterizes human rod-mediated vision, it has also been thought that night vision is very slow (taking up to 40 min) to adapt to changes in light levels. Even cone-mediated, daylight, vision has been thought to take 2 min to recover from light adaptation. Here, we show that most, though not all adaptation is rapid, taking less than 0.6 s. Thus, monochrome (black-white-gray) images can be presented at mesopic light levels and be visible within a few 10th of a second, even if the overall light level, or level of glare (as with passing headlamps while driving), changes abruptly.