scholarly journals Smooth Surface Visual Imaging Method for Eliminating High Reflection Disturbance

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4953
Author(s):  
Wei Shao ◽  
Kaibin Liu ◽  
Yunqiu Shao ◽  
Awei Zhou
Keyword(s):  
Surface Defects ◽  
Imaging System ◽  
High Light ◽  
Light Reflection ◽  
Imaging Method ◽  
Charge Coupled Device ◽  
Time Modulation ◽  
Time Space ◽  
Illumination Method ◽  
Visual Imaging

At present, visual imaging is widely applied for surface defects such as bumps and scratches in the manufacture of precise parts with a highly reflective surface. However, the high light reflection and halo disturbance as a result of the illumination in visual imaging exert a direct influence on the accuracy of defect detection. In this regard, the present paper develops an adaptive illumination method based on space–time modulation for a visual imaging system. Furthermore, a digital micro-mirror device (DMD) is employed to realize the pixel-level spatiotemporal modulation of illumination. Then, in combination with the illumination intensity feedback of charge coupled device (CCD), the time-space ratio is adjusted automatically to achieve adaptive uniform illumination and effectively suppress the high light reflection and halo disturbance of highly reflective surfaces. The experimental results show that, in terms of restraining high light disturbance, the visibility and accuracy of visual imaging are improved.

Research on Rail Surface Defect Inspection System

2012 ◽  
Vol 229-231 ◽  
pp. 1389-1393
Author(s):  
Yu Hu ◽  
Jian Xu Mao ◽  
Jian Pin Mao
Keyword(s):  
High Speed ◽  
Surface Defect ◽  
Surface Defects ◽  
Imaging System ◽  
Detection System ◽  
Inspection System ◽  
System Control ◽  
Visual Imaging ◽  
Automatic Detection System ◽  
Rail Surface Defect

In order to realize the inspection of rail surface defects with high speed and high precision, an automatic detection system based on machine vision is presented. The hardware structure of the system consists of the mechanical system, control system and visual imaging system. The software structure using histogram threshold segmentation, multi-structural morphological edge detection and other image processing methods to detect and identify defects automatically, and also built the simulation rail detection platform. The experimental results show that the cracks, scars and other detects can be accurately detected and extracted in real time, and meet the requirement of the rail surface inspection.

scholarly journals Hyperspectral Imaging Bioinspired by Chromatic Blur Vision in Color Blind Animals

Photonics ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 91
Author(s):  
Shuyue Zhan ◽  
Weiwen Zhou ◽  
Xu Ma ◽  
Hui Huang
Keyword(s):  
Hyperspectral Imaging ◽  
Imaging System ◽  
Light Flux ◽  
Image Sensor ◽  
High Light ◽  
Detection Sensitivity ◽  
Imaging Method ◽  
Inverse Filtering ◽  
Color Blind ◽  
Blurred Images

Hyperspectral imaging remote sensing is mutually restricted in terms of spatial and spectral resolutions, signal-to-noise ratio and exposure time. To deal with this trade-off properly, it is beneficial for imaging systems to have high light flux. In this paper, we put forward a novel hyperspectral imaging method with high light flux bioinspired by chromatic blur vision in color blind animals. We designed a camera lens with high degree of longitudinal chromatic aberration, a monochrome image sensor captured the chromatic blur images at different focal lengths. Finally, by using the known point spread functions of the chromatic blur imaging system, we process these chromatically blurred images by deconvolution based on singular value decomposition inverse filtering, and the spectral images of a target were restored. We constructed three different targets for validating image restoration based on a typical octopus eyeball imaging system. The results show that the proposed imaging method can effectively extract spectral images from the chromatically blurred images. This study can facilitate development of a novel bionic hyperspectral imaging, which may benefit from the high light flux of a large aperture and provide higher detection sensitivity.

scholarly journals Optical Aberration Calibration and Correction of Photographic System Based on Wavefront Coding

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4011
Author(s):  
Chuanwei Yao ◽  
Yibing Shen
Keyword(s):  
Imaging System ◽  
Optical Design ◽  
Computational Imaging ◽  
Large Field ◽  
Wavefront Aberration ◽  
Imaging Method ◽  
Image Deconvolution ◽  
Pupil Function ◽  
Wavefront Coding ◽  
Blurred Images

The image deconvolution technique can recover potential sharp images from blurred images affected by aberrations. Obtaining the point spread function (PSF) of the imaging system accurately is a prerequisite for robust deconvolution. In this paper, a computational imaging method based on wavefront coding is proposed to reconstruct the wavefront aberration of a photographic system. Firstly, a group of images affected by local aberration is obtained by applying wavefront coding on the optical system’s spectral plane. Then, the PSF is recovered accurately by pupil function synthesis, and finally, the aberration-affected images are recovered by image deconvolution. After aberration correction, the image’s coefficient of variation and mean relative deviation are improved by 60% and 30%, respectively, and the image can reach the limit of resolution of the sensor, as proved by the resolution test board. Meanwhile, the method’s robust anti-noise capability is confirmed through simulation experiments. Through the conversion of the complexity of optical design to a post-processing algorithm, this method offers an economical and efficient strategy for obtaining high-resolution and high-quality images using a simple large-field lens.

scholarly journals Thermal Analysis of Stomatal Response under Salinity and High Light

2021 ◽  
Vol 22 (9) ◽  
pp. 4663
Author(s):  
Aleksandra Orzechowska ◽  
Martin Trtílek ◽  
Krzysztof Michał Tokarz ◽  
Renata Szymańska ◽  
Ewa Niewiadomska ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Initial Response ◽  
Co2 Assimilation ◽  
High Light ◽  
Stomatal Aperture ◽  
Imaging Method ◽  
Stomatal Response ◽  
Time Constants ◽  
Net Co2 Assimilation ◽  
Temporary Response

A non-destructive thermal imaging method was used to study the stomatal response of salt-treated Arabidopsis thaliana plants to excessive light. The plants were exposed to different levels of salt concentrations (0, 75, 150, and 220 mM NaCl). Time-dependent thermograms showed the changes in the temperature distribution over the lamina and provided new insights into the acute light-induced temporary response of Arabidopsis under short-term salinity. The initial response of plants, which was associated with stomatal aperture, revealed an exponential growth in temperature kinetics. Using a single-exponential function, we estimated the time constants of thermal courses of plants exposed to acute high light. The saline-induced impairment in stomatal movement caused the reduced stomatal conductance and transpiration rate. Limited transpiration of NaCl-treated plants resulted in an increased rosette temperature and decreased thermal time constants as compared to the controls. The net CO2 assimilation rate decreased for plants exposed to 220 mM NaCl; in the case of 75 mM NaCl treatment, an increase was observed. A significant decline in the maximal quantum yield of photosystem II under excessive light was noticeable for the control and NaCl-treated plants. This study provides evidence that thermal imaging as a highly sensitive technique may be useful for analyzing the stomatal aperture and movement under dynamic environmental conditions.

scholarly journals Synthetic polarization-sensitive optical coherence tomography by deep learning

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yi Sun ◽  
Jianfeng Wang ◽  
Jindou Shi ◽  
Stephen A. Boppart
Keyword(s):  
Optical Coherence Tomography ◽  
Deep Learning ◽  
Imaging System ◽  
Imaging Modality ◽  
Similarity Index ◽  
Polarization Sensitivity ◽  
Imaging Method ◽  
Optical Coherence ◽  
The Real ◽  
Oct Imaging

AbstractPolarization-sensitive optical coherence tomography (PS-OCT) is a high-resolution label-free optical biomedical imaging modality that is sensitive to the microstructural architecture in tissue that gives rise to form birefringence, such as collagen or muscle fibers. To enable polarization sensitivity in an OCT system, however, requires additional hardware and complexity. We developed a deep-learning method to synthesize PS-OCT images by training a generative adversarial network (GAN) on OCT intensity and PS-OCT images. The synthesis accuracy was first evaluated by the structural similarity index (SSIM) between the synthetic and real PS-OCT images. Furthermore, the effectiveness of the computational PS-OCT images was validated by separately training two image classifiers using the real and synthetic PS-OCT images for cancer/normal classification. The similar classification results of the two trained classifiers demonstrate that the predicted PS-OCT images can be potentially used interchangeably in cancer diagnosis applications. In addition, we applied the trained GAN models on OCT images collected from a separate OCT imaging system, and the synthetic PS-OCT images correlate well with the real PS-OCT image collected from the same sample sites using the PS-OCT imaging system. This computational PS-OCT imaging method has the potential to reduce the cost, complexity, and need for hardware-based PS-OCT imaging systems.

scholarly journals A New Stitching Method for Dark-Field Surface Defects Inspection Based on Simplified Target-Tracking and Path Correction

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 448
Author(s):  
Chen ◽  
Li ◽  
Sui
Keyword(s):  
Target Tracking ◽  
Surface Defects ◽  
Imaging System ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Fine Surface ◽  
Camera Perspective ◽  
Scanning Path ◽  
Field Imaging ◽  
Small Field Of View

A camera-based dark-field imaging system can effectively detect defects of microns on large optics by scanning and stitching sub-apertures with a small field of view. However, conventional stitching methods encounter problems of mismatches and location deviations, since few defects exist on the tested fine surface. In this paper, a highly efficient stitching method is proposed, based on a simplified target-tracking and adaptive scanning path correction. By increasing the number of sub-apertures and switching to camera perspective, the defects can be regarded as moving targets. A target-tracking procedure is firstly performed to obtain the marked targets. Then, the scanning path is corrected by minimizing the sum of deviations. The final stitching results are updated by re-using the target-tracking method. An experiment was carried out on an inspection of our specially designed testing sample. Subsequently, 118 defects were identified out of 120 truly existing defects, without stitching mismatches. The experiment results show that this method can help to reduce mismatches and location deviations of defects, and it was also effective in increasing the detectability for weak defects.

scholarly journals In Situ Image Acquisition and Measurement of Microdroplets Based on Delay Triggering

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 148
Author(s):  
Xuefeng Chang ◽  
Kang Zheng ◽  
Dan Xie ◽  
Xiayun Shu ◽  
Keyu Xu ◽  
...  
Keyword(s):  
Light Source ◽  
Delay Time ◽  
Imaging System ◽  
Image Acquisition ◽  
Ccd Camera ◽  
Time Interval ◽  
Charge Coupled Device ◽  
Drop On Demand ◽  
Relative Standard

An in situ image acquisition apparatus based on delay triggering for visualizing microdroplets formation is described. The imaging system includes a charge-coupled device camera, a motion control card, a driving circuit, a time delay triggering circuit, and a light source. By adjusting the varying trigger delay time which is synchronized with respect to the signal for jetting, the steady sequential images of the droplet flying in free space can be captured real-time by the system. Several image processing steps are taken to measure the diameters and coordinates of the droplets. Also, the jetting speeds can be calculated according to the delay time interval. For glycerin/water (60:40, mass ratio), under the given conditions of the self-made pneumatically diaphragm-driven drop-on-demand inkjet apparatus, the average of diameter and volume are measured as 266.8 μm and 9944 pL, respectively, and the maximum average velocity of the microdroplets is 0.689 m/s. Finally, the imaging system is applied to measure the volume of 200 microsolder balls generated from the inkjet apparatus. The average diameter is 87.96 μm, and the relative standard deviation is 0.83%. The results show good reproducibility. Unlike previous stroboscopic techniques, the present in situ imaging system which is absence of instantaneous high intensity light employs two control signals to stimulate the microdroplet generator and the charge-coupled device (CCD) camera. Hence, the system can avoid the desynchronization problem of signals which control the strobe light-emitting diode (LED) light source and the camera in previous equipment. This technology is a reliable and cost-effective approach for capturing and measuring microdroplets.

scholarly journals A Quantitative Method to Measure Low Levels of ROS in Nonphagocytic Cells by Using a Chemiluminescent Imaging System

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jun-Sub Kim ◽  
Kyuho Jeong ◽  
James M. Murphy ◽  
Yelitza A. R. Rodriguez ◽  
Ssang-Taek Steve Lim
Keyword(s):  
Real Time ◽  
Intracellular Signaling ◽  
Imaging System ◽  
Low Cost ◽  
Fiber Formation ◽  
Imaging Method ◽  
Actin Stress Fiber ◽  
Dependent Manner ◽  
Protein Tyrosine ◽  
Low Levels

Chemiluminescence (CL) is one of the most useful methods for detecting reactive oxygen species (ROS). Although fluorescence dyes or genetically encoded biosensors have been developed, CL is still used due to its high sensitivity, ease of use, and low cost. While initially established and used to measure high levels of ROS in phagocytic cells, CL assays are not ideal for measuring low levels of ROS. Here, we developed a newly modified CL assay using a chemiluminescent imaging system for measuring low concentrations of ROS in nonphagocytic cells. We found that dissolving luminol in NaOH, rather than DMSO, increased the H2O2-induced CL signal and that the addition of 4-iodophenylboronic acid (4IPBA) further increased CL intensity. Our new system also increased the rate and intensity of the CL signal in phorbol 12-myristate 13-acetate- (PMA-) treated HT-29 colon cancer cells compared to those in luminol only. We were able to quantify ROS levels from both cells and media in parallel using an H2O2standard. A significant benefit to our system is that we can easily measure stimulus-induced ROS formation in a real-time manner and also investigate intracellular signaling pathways from a single sample simultaneously. We found that PMA induced tyrosine phosphorylation of protein tyrosine kinases (PTKs), such as focal adhesion kinase (FAK), protein tyrosine kinase 2 (Pyk2), and Src, and increased actin stress fiber formation in a ROS-dependent manner. Interestingly, treatment with either N-acetyl-L-cysteine (NAC) or diphenyleneiodonium (DPI) reduced the PMA-stimulated phosphorylation of these PTKs, implicating a potential role in cellular ROS signaling. Thus, our newly optimized CL assay using 4IPBA and a chemiluminescent imaging method provides a simple, real-time, and low-cost method for the quantification of low levels of ROS.

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