Research on Magnet Excitation and Image Processing Used in Visual Detection

2011 ◽  
Vol 216 ◽  
pp. 793-797
Author(s):  
Li Bing Bai ◽  
Shu Lin Tian ◽  
Yu Hua Cheng
Keyword(s):  
Image Processing ◽  
Eddy Current ◽  
Visual Detection ◽  
Polarized Light ◽  
Ccd Camera ◽  
Experimental Tests ◽  
Laser Source ◽  
Magnetic Excitation ◽  
Charge Coupled Device ◽  
A Charge

A novel visual detection set, which can detect sub-superficial defects in conductive specimens, is presented in this paper. The set has a laser source, a charge coupled device (CCD) camera, and a magnetic excitation. The linear polarized light given off by the laser source is modulated by the superimposition of the magnetic fields induced by the coil and eddy current, and acquired by the CCD. Given the exciting current is known and the eddy current is influenced by the defects, the information of defects can be extracted from the image acquired by CCD. The magnet excitation and image processing are described in detail. Experimental tests have been done and the method presented is proved by the experimental results.

Using laser speckle to measure the roughness of paper

TAPPI Journal ◽  
2011 ◽  
Vol 10 (3) ◽  
pp. 7-13
Author(s):  
ABDIEL PINO ◽  
JOSEP PLADELLORENS ◽  
JOSEP F. COLOM ◽  
ORIOL CUSOLA ◽  
AGUSTÍN TOSAS
Keyword(s):  
Image Processing ◽  
Speckle Pattern ◽  
Ccd Camera ◽  
Laser Speckle ◽  
Charge Coupled Device ◽  
Paper Surface ◽  
Surface Profiling ◽  
Base Paper ◽  
Occurrence Matrix ◽  
A Charge

Paper surface roughness is an important consideration in paper and board destined for printing. The amount of coating and method of application depend on the roughness of the base paper. We present a method to measure the roughness of the paper based on analysis of speckle pattern on the surface. Images are captured by means of a simple configuration using a laser and a charge-coupled device (CCD) camera. Then, we apply digital image processing using a co-occurrence matrix, providing for a noncontact surface profiling method that can be used online.

scholarly journals Spectroscopic flat-fields can be used for precision CCD gain and noise tests

2021 ◽  
Vol 38 ◽  
Author(s):  
J. Gordon Robertson
Keyword(s):  
Ccd Camera ◽  
Matched Pair ◽  
Optical Fibres ◽  
Charge Coupled Device ◽  
Small Areas ◽  
Flat Field ◽  
Basic Parameters ◽  
The Mean ◽  
A Charge ◽  
Analogue To Digital

Abstract One of the basic parameters of a charge coupled device (CCD) camera is its gain, that is, the number of detected electrons per output Analogue to Digital Unit (ADU). This is normally determined by finding the statistical variances from a series of flat-field exposures with nearly constant levels over substantial areas, and making use of the fact that photon (Poisson) noise has variance equal to the mean. However, when a CCD has been installed in a spectroscopic instrument fed by numerous optical fibres, or with an echelle format, it is no longer possible to obtain illumination that is constant over large areas. Instead of making do with selected small areas, it is shown here that the wide variation of signal level in a spectroscopic ‘flat-field’ can be used to obtain accurate values of the CCD gain, needing only a matched pair of exposures (that differ in their realisation of the noise). Once the gain is known, the CCD readout noise (in electrons) is easily found from a pair of bias frames. Spatial stability of the image in the two flat-fields is important, although correction of minor shifts is shown to be possible, at the expense of further analysis.

scholarly journals Neutron imager with micro channel plates (MCP) in electrostatic mirror configuration: Experimental test with radiation source

2018 ◽  
Vol 48 ◽  
pp. 1860120
Author(s):  
V. Variale ◽  
B. Skarbo
Keyword(s):  
Neutron Beam ◽  
Ccd Camera ◽  
Experimental Tests ◽  
Micro Channel ◽  
Spatial Profile ◽  
Critical Feature ◽  
Neutron Beams ◽  
Channel Plate ◽  
A Charge ◽  
Electrostatic Mirror

The design of a new high-transparency device based on a Micro Channel Plate (MCP) detector was recently proposed for monitoring the flux and beam spatial profile of neutron beams. The proposed device consists of a very thin aluminum (Al) foil (with a [Formula: see text]Li deposit) placed in the neutron beam and an MCP detector equipped with a phosphor-screen readout linked to a charge-coupled device (CCD) camera outside the neutron beam. A critical feature of this device is that it uses an electrostatic mirror to minimize the perturbation of the neutron beam (i.e., absorption and scattering). It can be used at existing neutron time-of-flight (n_TOF) facilities (in particular at the n_TOF facility at CERN) for monitoring the flux and spatial profile of neutron beams in the thermal and epithermal region. The experimental tests conducted for this study using a radioactive source to determine the behavior of the electrostatic mirror behavior will be presented and discussed in this paper.

scholarly journals Development and Certification of A Visibility-Range Monitor By Image Processing

1989 ◽  
Vol 13 ◽  
pp. 117-119
Author(s):  
Keishi Ishimoto ◽  
Masao Takeuchi ◽  
Shigeyuki Naitou ◽  
Haruki Furusawa
Keyword(s):  
Image Processing ◽  
Vertical Distribution ◽  
Video Camera ◽  
Measuring System ◽  
Blowing Snow ◽  
Snow Surface ◽  
Charge Coupled Device ◽  
Visibility Range ◽  
A Charge ◽  
The Vertical Distribution

A new visibility-range measuring system has been developed which uses a video camera, and with which visibility can be estimated by measuring the brightness contrast of a black target against a standardized background. This principle has been applied to development of the new visibility-range monitor described in this paper. In this monitor, a charge-coupled device (CCD) video camera measures the brightness of an arbitrary area in its range of vision, and visibility range measured by the video camera in blowing snow can be compared with that measured by the transmissometer-type visibility-range monitor and can also be calculated by direct observation using optical targets. The new sytem can monitor visibility and record information about traffic on highways at 1 s intervals for a maximum of six separate positions. The vertical distribution of visibilities over a snow surface has been observed, and it has been found that the fluctuation in visibility is greatest at lower levels above the ground in blowing snow.

Description And Preliminary Performance Of A Charge-Coupled Device (CCD) Camera

1981 ◽  
Author(s):  
A. Bouere ◽  
J. Cretolle ◽  
B. Fort ◽  
R. Jouan ◽  
M. Gorisse ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Charge Coupled Device ◽  
A Charge

Research on the High-Speed Object Shadowgraph Image Processing Method Based on Adaptive Threshold Segmentation

2013 ◽  
Vol 325-326 ◽  
pp. 1571-1575
Author(s):  
Fang Wang ◽  
Zong Wei Yang ◽  
De Ren Kong ◽  
Yun Fei Jia
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Center Of Mass ◽  
Image Data ◽  
Ccd Camera ◽  
Adaptive Threshold ◽  
Processing Method ◽  
Laser Source ◽  
Feature Points ◽  
Threshold Segmentation

Shadowgraph is an important method to obtain the flight characteristics of high-speed object, such as attitude and speed etc. To get the contour information of objects and coordinates of feature points from shadowgraph are the precondition of characteristics analysis. Current digital shadowgraph system composed of CCD camera and pulsed laser source is widely used, but still lack of the corresponding method in image processing. Therefore, the selection of an effective processing method in order to ensure high effectiveness and accuracy of image data interpretation is an urgent need to be solved. According to the features of shadowgraph, a processing method to realize the contour extraction of high-speed object by adaptive threshold segmentation is proposed based on median filtering in this paper, and verified with the OpenCV in VC environment, the identification process of the feature points are recognized. The result indicates that by using this method, contours of high-speed objects can be detected nicely, to combine relevant algorithm, the pixel coordinates of feature points such as the center of mass can be recognized accurately.

scholarly journals Development and Certification of A Visibility-Range Monitor By Image Processing

1989 ◽  
Vol 13 ◽  
pp. 117-119
Author(s):  
Keishi Ishimoto ◽  
Masao Takeuchi ◽  
Shigeyuki Naitou ◽  
Haruki Furusawa
Keyword(s):  
Image Processing ◽  
Vertical Distribution ◽  
Video Camera ◽  
Measuring System ◽  
Blowing Snow ◽  
Snow Surface ◽  
Charge Coupled Device ◽  
Visibility Range ◽  
A Charge ◽  
The Vertical Distribution

A new visibility-range measuring system has been developed which uses a video camera, and with which visibility can be estimated by measuring the brightness contrast of a black target against a standardized background. This principle has been applied to development of the new visibility-range monitor described in this paper. In this monitor, a charge-coupled device (CCD) video camera measures the brightness of an arbitrary area in its range of vision, and visibility range measured by the video camera in blowing snow can be compared with that measured by the transmissometer-type visibility-range monitor and can also be calculated by direct observation using optical targets.The new sytem can monitor visibility and record information about traffic on highways at 1 s intervals for a maximum of six separate positions. The vertical distribution of visibilities over a snow surface has been observed, and it has been found that the fluctuation in visibility is greatest at lower levels above the ground in blowing snow.

Single-Shot Multiwavelength Imaging of Laser Plumes

1998 ◽  
Vol 52 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Matthew P. Nelson ◽  
Wendy C. Bell ◽  
Michael L. McLester ◽  
M. L. Myrick
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Ccd Camera ◽  
Chemical Imaging ◽  
Single Shot ◽  
Charge Coupled Device ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Optic Array ◽  
A Charge

A novel optical approach to single-shot chemical imaging with high spectroscopic resolution is described with the use of a prototype dimension-reduction fiber-optic array. Images are focused onto a 30 × 20 array of hexagonally packed 250 μm o.d. f/2 optical fibers that are drawn into a 600 × 1 distal array with specific ordering. The 600 × 1 side of the array is imaged with an f/2 spectrograph equipped with a holographic grating and a charge-coupled device (CCD) camera for spectral analysis. Software is used to extract the spatial/spectral information contained in the CCD images and de-convolute them into wavelength-specific reconstructed images or position-specific spectra that span a 190 nm wavelength space. “White light” zero-order images and first-order spectroscopic images of laser plumes have been reconstructed to illustrate proof-of-principle. Index Headings: Fiber optics; Chemical imaging; Spectroscopic imaging; Charged-coupled device (CCD); Laser-induced breakdown spectroscopy (LIBS).

Profiling of Redox Atmosphere in Flames by Chemical Seeding/Planar Laser-Induced Fluorescence (CS/PLIF)

2005 ◽  
Vol 128 (4) ◽  
pp. 765-772 ◽  
Author(s):  
K. Kitagawa ◽  
S. Itoh ◽  
N. Arai ◽  
Ashwani K. Gupta
Keyword(s):  
Rotational Temperature ◽  
Thermal Dissociation ◽  
Flame Temperature ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Charge Coupled Device ◽  
Planar Laser ◽  
A Charge ◽  
Local Value ◽  
Redox Index

Knowledge on the local value of reducing and oxidizing (redox) atmospheres in flames is among the most important issues to be desired by combustion engineers. In this study, the spatial distribution of a redox atmosphere in flames has been measured experimentally by the chemical seeding/laser-induced fluorescence (CS/LIF) technique. A solution of iron was sprayed into a premixed propane-air flame supported on a slot burner. The LIF intensity of FeO band was compared to that of a Fe line to estimate the experimentally determined degree of atomization in the reaction FeO→Fe+O. The flame temperature profile was determined as a rotational temperature and was obtained by comparing the LIF (laser-induced fluorescence) intensities of OH rotational lines. The degree of atomization was theoretically calculated on the basis that simple thermal dissociation takes place in the reaction. The redox atmosphere, or a redox index, is defined as the ratio of the experimentally determined to theoretically calculated degrees of atomization. Two-dimensional distributions or profiles of the excitation temperature, experimentally determined degree of atomization, and redox index have been measured using a charge coupled device (CCD) camera fitted with an optical bandpass filter and the associated signal processing using a computer. This method has been successfully applied to quantitatively illustrate the local atmosphere and profile of the redox atmosphere in flames.

Image Information Obtained Using a Charge-Coupled Device (CCD) Camera During an Immersion Liquid Evaporation Process for Measuring the Refractive Index of Solid Particles

2018 ◽  
Vol 72 (6) ◽  
pp. 908-912 ◽  
Author(s):  
Ilpo Niskanen ◽  
Veijo Sutinen ◽  
Göran Thungström ◽  
Jukka Räty
Keyword(s):  
Refractive Index ◽  
Physical Property ◽  
Ccd Camera ◽  
Solid Particles ◽  
Evaporation Process ◽  
Immersion Liquid ◽  
Refractive Index Measurement ◽  
Charge Coupled Device ◽  
Liquid Evaporation ◽  
A Charge

The refractive index is a fundamental physical property of a medium, which can be used for the identification and purity issues of all media. Here we describe a refractive index measurement technique to determine simultaneously the refractive index of different solid particles by monitoring the transmittance of light from a suspension using a charge-coupled device (CCD) camera. An important feature of the measurement is the liquid evaporation process for the refractive index matching of the solid particle and the immersion liquid; this was realized by using a pair of volatile and non-volatile immersion liquids. In this study, refractive indices of calcium fluoride (CaF2) and barium fluoride (BaF2) were determined using the proposed method.

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