Detection of Region-of-Interest Based on Noise Filtering in High-Speed Images

Author(s):  
Seok-Woo Jang
2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Emanuele Rizzuto ◽  
Silvia Carosio ◽  
Martina Faraldi ◽  
Simona Pisu ◽  
Antonio Musarò ◽  
...  

Tissue engineering is a multidisciplinary science based on the application of engineering approaches to biologic tissue formation. Engineered tissue internal organization represents a key aspect to increase biofunctionality before transplant and, as regarding skeletal muscles, the potential of generating contractile forces is dependent on the internal fiber organization and is reflected by some macroscopic parameters, such as the spontaneous contraction. Here we propose the application of digital image correlation (DIC) as an independent tool for an accurate and noninvasive measurement of engineered muscle tissue spontaneous contraction. To validate the proposed technique we referred to the X-MET, a promising 3-dimensional model of skeletal muscle. The images acquired through a high speed camera were correlated with a custom-made algorithm and the longitudinal strain predictions were employed for measuring the spontaneous contraction. The spontaneous contraction reference values were obtained by studying the force response. The relative error between the spontaneous contraction frequencies computed in both ways was always lower than 0.15%. In conclusion, the use of a DIC based system allows for an accurate and noninvasive measurement of biological tissues’ spontaneous contraction, in addition to the measurement of tissue strain field on any desired region of interest during electrical stimulation.


2006 ◽  
Author(s):  
Balaji Gopalan ◽  
Edwin Malkiel ◽  
Joseph Katz

We study the diffusion of slightly buoyant droplets in isotropic turbulence using High Speed Digital Holographic PIV. Droplets (Specific Gravity 0.85) are injected in the central portion of an isotropic turbulence facility with weak mean flow. Perpendicular digital inline holograms are recorded in a 37 × 37 × 37 mm3 region of interest using two high speed cameras. Data are recorded at 250 frames per second (2000 frames per second is the maximum possible frame rate). An automated program is developed to obtain two dimensional tracks of the droplets from two orthogonal images and match them to get three dimensional tracks. Cross correlation of droplet images are used for measuring their velocities. The time series are low pass filtered to obtain accurate time history of droplet velocities. Data analysis determines the PDF of velocity and acceleration in three dimensions. The time history also enables us to calculate the three dimensional Lagrangian velocity autocorrelation function for different droplet radii. Integration of these functions gives us the diffusion coefficients. For shorter time scales, when the diffusion need not be Fickian we can use the three dimensional trajectories to calculate the generalized dispersion tensor and measure the time elapsed for diffusion to become Fickian.


2020 ◽  
Vol 53 (3-4) ◽  
pp. 757-763
Author(s):  
Jingbo Xu ◽  
Xiaomeng Cui ◽  
Wenbo Ma

Changes in temperature and stress will lead to the rail creeping of high-speed railway, which becomes a hidden danger in the operation of trains. This paper studies a real-time visual measurement system for creeping displacement monitoring. The bilateral line extraction to determine the target location overcomes the influence of ambient light on image grayscale. The dynamic region of interest setting method is produced to lock and track the target. The self-calibration technology makes the system suitable for field application. The remote transmission of monitoring data is realized through narrow band internet of things (NB-IOT). These methods solve the problems in practical application. The monitoring system provides a reliable guarantee for the safe and stable operation of high-speed railway.


Circuit World ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 133-136 ◽  
Author(s):  
Ge Qiang ◽  
Zheng Shanshan ◽  
Zhao Yang ◽  
Chen Mao

Purpose – This paper aims to propose image stitching by reduction of full line and taking line image as registration image to solve the problem of automatic optic inspection in PCB detection. In addition, surf registration was introduced for image stitching to improve the accuracy and speed of stitching. Design/methodology/approach – First, image stitching proceeded by method of full line reduction and taking line image as registration image; second, surf registration was introduced based on the traditional PCB image stitching algorithm. Scale space of the image pyramid was adopted for confirming relative future points between stitching image. The registration means of nearest neighbourhood and next neatest neighborhood was selected for feature matching and fused in region of interest to fulfil image stitching. Findings – The improved stitching algorithm with small data size of image, high speed and noncumulative transitive error eliminated displacement deviation and solved the stitching gap caused by uneven illumination, to greatly improve the accuracy and speed of stitching. Research limitations/implications – The research of this paper can only used for appearance detection and cannot be used for solder joint inspection with circuit detection or invisible solder joint detection; it can identify and mark PCB component defects but cannot classify automatically, thus artificial confirmation and processing is needed. Originality/value – Based on the traditional image stitching means, this paper proposed full line reduction for image stitching, which reduces processing of data and speeds up image stitching; in addition, surf registration was introduced into the study of PCB stitching algorithm, which greatly improves the accuracy and speed of stitching and solves stitching gap formed by opposite variation trend of image local edge caused by uneven illumination.


2021 ◽  
Vol 7 (11) ◽  
pp. 223
Author(s):  
Gabriele Antonio De Vitis ◽  
Antonio Di Tecco ◽  
Pierfrancesco Foglia ◽  
Cosimo Antonio Prete

During the production of pharmaceutical glass tubes, a machine-vision based inspection system can be utilized to perform the high-quality check required by the process. The necessity to improve detection accuracy, and increase production speed determines the need for fast solutions for defects detection. Solutions proposed in literature cannot be efficiently exploited due to specific factors that characterize the production process. In this work, we have derived an algorithm that does not change the detection quality compared to state-of-the-art proposals, but does determine a drastic reduction in the processing time. The algorithm utilizes an adaptive threshold based on the Sigma Rule to detect blobs, and applies a threshold to the variation of luminous intensity along a row to detect air lines. These solutions limit the detection effects due to the tube’s curvature, and rotation and vibration of the tube, which characterize glass tube production. The algorithm has been compared with state-of-the-art solutions. The results demonstrate that, with the algorithm proposed, the processing time of the detection phase is reduced by 86%, with an increase in throughput of 268%, achieving greater accuracy in detection. Performance is further improved by adopting Region of Interest reduction techniques. Moreover, we have developed a tuning procedure to determine the algorithm’s parameters in the production batch change. We assessed the performance of the algorithm in a real environment using the “certification” functionality of the machine. Furthermore, we observed that out of 1000 discarded tubes, nine should not have been discarded and a further seven should have been discarded.


Author(s):  
Jesus D. Ortega ◽  
Guillermo Anaya ◽  
Peter Vorobieff ◽  
Gowtham Mohan ◽  
Clifford K. Ho

Abstract The Falling Particle Receiver (FPR) at the National Solar Thermal Test Facility (NSTTF) is a testbed for promising receiver technologies offering solutions to the temperature and irradiance limitations exhibited by gas and molten salt receivers, since the particle curtain is directly irradiated without the need of containment. Until recently, the heat loss of the NSTTF 1 MWth FPR was not fully characterized. One of the challenges of the FPR characterization is the intricate flow conditions that the particle curtain experiences due to its cavity design with a single open aperture, to allow the direct irradiance. Recently, particle plumes expelled from the FPR during operation were observed. While this phenomenon affects the FPR heat loss and needs to be closely monitored, it is extremely difficult to operate any kind of sensors near the aperture of the FPR. This work describes the development of a methodology using a high-speed IR camera, located ≥ 5 meters away from the aperture, to estimate the opacity of a particle plume, which in turn can be used to extract the average particle temperature of a region of interest with a known background temperature. Experiments performed at the University of New Mexico using four different flow configurations and three different temperatures (200, 450, and 750°C) were conducted to determine the relationship between the plume opacity in the visible range and the “particle-pixel” opacity obtained from thermograms in the IR range. We present a “particle-pixel function” that describes the combined impact of an unknown number of particles at a specific temperature on a thermogram pixel value with an initial value equal to the background temperature. The novelty of this function is that it provides a reasonable estimate of the plume opacity using thermograms obtained from the IR camera; hence a bulk particle temperature can be obtained. Future development of this methodology will make it possible to compute the advective losses from the FPR and provide a first order approximation of the convective losses for the system.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Turgay Koç ◽  
Tolga Çiloğlu

An automatic method for segmenting glottis in high speed endoscopic video (HSV) images of vocal folds is proposed. The method is based on image histogram modeling. Three fundamental problems in automatic histogram based processing of HSV images, which are automatic localization of vocal folds, deformation of the intensity distribution by nonuniform illumination, and ambiguous segmentation when glottal gap is small, are addressed. The problems are solved by using novel masking, illumination, and reflectance modeling methods. The overall algorithm has three stages: masking, illumination modeling, and segmentation. Firstly, a mask is determined based on total variation norm for the region of interest in HSV images. Secondly, a planar illumination model is estimated from consecutive HSV images and reflectance image is obtained. Reflectance images of the masked HSV are used to form a vertical slice image whose reflectance distribution is modeled by a Gaussian mixture model (GMM). Finally, estimated GMM is used to isolate the glottis from the background. Results show that proposed method provides about 94% improvements with respect to manually segmented data in contrast to conventional method which uses Rayleigh intensity distribution in extracting the glottal areas.


Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5058
Author(s):  
Long Tian ◽  
Jianhui Zhao ◽  
Bing Pan ◽  
Zhaoyang Wang

Video deflectometer based on using off-axis digital image correlation (DIC) has emerged as a robust non-contact optical tool for deflection measurements of bridges. In practice, a video deflectometer often needs to measure the deflections at multiple positions of the bridge. The existing 2D-DIC-based measurement methods usually use a laser rangefinder to measure the distance from each point to the camera to obtain the scale factor for the point. It is only suitable for the deflection measurements of a few points since manually measuring distances for a large number of points is time consuming and impractical. In this paper, a novel method for full-field bridge deflection measurement based on off-axis DIC is proposed. Because the bridge is usually a slender structure and the region of interest on the bridge is often a narrow band, the new approach can determine the scale factors of all the points of interest with a spatial straight-line fitting scheme. Moreover, the proposed technique employs reliability-guided processing and a fast initial parameter estimation strategy for real-time and accurate image-matching analysis. An indoor cantilever beam experiment verified the accuracy of the proposed approach, and a field test of a high-speed railway bridge demonstrated the robustness and practicability of the technique.


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