scholarly journals Combining off- and on-line calibration of a digital camera

2002 ◽  
Author(s):  
M. Urbanek ◽  
R. Horaud ◽  
P. Sturm
Keyword(s):  
Digital Camera ◽  
On Line

Design of On-Line Detection System for Paper Defects Based on Line-Scan Camera

2014 ◽  
Vol 536-537 ◽  
pp. 268-271
Author(s):  
Ping He ◽  
Chao Liu ◽  
Meng Wang ◽  
Sheng Mei Cao
Keyword(s):  
High Efficiency ◽  
Detection System ◽  
Low Cost ◽  
Digital Camera ◽  
Line Detection ◽  
Detection Scheme ◽  
Line Scan ◽  
On Line ◽  
Increasing Demand ◽  
Technology Level

Paper defects mean that there are some defects in the paper such as hole, emboss, and fold during the paper production, which mainly results from the limitation of technological level. In the past time, artificial visual inspection and off-line checking were often used to detect the paper defects. However, its shortcoming was highlighted along with the improvement of industrial technology level and increasing demand for paper. In order to realize the online detection and markers for paper defects, the project designs the on-line detection system based on line-scan digital camera. Firstly, the principle and detection scheme of the system for the paper defects was presented. Then the overall structure of the system was designed. After that, the hardware circuit of the system was designed using TMS320F2812 as main control chip. It mainly consists of the function of each module and the working process of the system. Finally, the software of the image acquisition system was presented. With the experimental verification, the system has advantages of low cost, high efficiency and strong resistance to interference. The functions and indexes achieved the design requirements.

scholarly journals Spectral diagnosis of a laser-produced XUV source using a digital camera system with pinhole transmission grating

1991 ◽  
Vol 9 (2) ◽  
pp. 593-601 ◽  
Author(s):  
N. Böwering ◽  
T. Döhring ◽  
U. Gärner ◽  
U. Heinzmann
Keyword(s):  
Detection System ◽  
Digital Camera ◽  
Ccd Camera ◽  
Liquid Lead ◽  
Camera System ◽  
Transmission Grating ◽  
Long Term Stability ◽  
On Line ◽  
Spectral Diagnosis

For spectral diagnosis, a repetitive laser-produced soft-X-ray source was examined in the range 2–40 nm using a spectrometer containing a pinhole transmission grating, an image converter, and a CCD camera. Via digital recording the detection system provides fast on-line data accumulation with spectral and spatial resolution. With this detector the performance of the light source was studied with respect to spectral emission characteristics, long-term stability, and reproducibility by recording spectra for different solid targets and liquid lead.

Sludge settleability detection using automated SV30 measurement and its application to a field WWTP

2011 ◽  
Vol 64 (8) ◽  
pp. 1743-1749 ◽  
Author(s):  
Y. J. Kim ◽  
S. J. Choi ◽  
H. Bae ◽  
C. W. Kim
Keyword(s):  
Wastewater Treatment Plants ◽  
Digital Camera ◽  
Detection Algorithm ◽  
Field Application ◽  
Automated Detection ◽  
Image Capture ◽  
On Line ◽  
Analysis Of The Images ◽  
Sludge Settling ◽  
Sludge Settleability

The need for automation & measurement technologies to detect the process state has been a driving force in the development of various measurements at wastewater treatment plants. While the number of applications of automation & measurement technologies to the field is increasing, there have only been a few cases where they have been applied to the area of sludge settling. This is because it is not easy to develop an automated operation support system for the detection of sludge settleability due to its site-specific characteristics. To automate the human operator's daily test and diagnosis works on sludge settling, an on-line SV30 measurement was developed and an automated detection algorithm on settleability was developed that imitated heuristics to detect settleability faults. The automated SV30 measurement is based on automatic pumping with a predefined schedule, the image capture of the settling test with a digital camera, and an analysis of the images to detect the settled sludge height. A sludge settleability detection method was developed and its applicability was investigated by field application.

MONITORING AND BREAKTHROUGH CONTROL OF LASER DRILLED HOLES BY MEANS OF MACHINE VISION

2013 ◽  
Vol 37 (3) ◽  
pp. 355-363
Author(s):  
Chao-Ching Ho ◽  
Yuan-Jen Chang ◽  
Jin-Chen Hsu ◽  
Chia-Lung Kuo ◽  
Jun-Jia He
Keyword(s):  
Material Removal ◽  
Removal Rate ◽  
Digital Camera ◽  
Hole Drilling ◽  
Laser Operation ◽  
Visual Monitoring ◽  
Laser Induced Plasma ◽  
Working Surface ◽  
On Line ◽  
Through Hole

An on-line monitoring system for breakthrough detection in laser drilling is proposed to maximize the material removal rate and energy efficiency of laser through-hole drilling. The system is based on visual monitoring of the working surface using a digital camera, coupled with microcontroller control of the drilling laser operation. The camera is installed adjacent to the entry surface of the workpiece, and the spatial extend of the laser-induced plasma at the working site is monitored radially as the criterion for breakthrough detection. Experimental results show that the proposed system successfully detects when the laser beam has broken through a workpiece, and turns off the laser automatically by feedback control.

An Enhanced On-Line Service for 3D Model Construction from Photographs

2012 ◽  
Vol 1 (2) ◽  
pp. 277-294 ◽  
Author(s):  
David Tingdahl ◽  
Gool Van Luc
Keyword(s):  
3D Reconstruction ◽  
Web Service ◽  
Camera Calibration ◽  
3D Model ◽  
Digital Camera ◽  
Calibration Method ◽  
Complete Model ◽  
On Line ◽  
Automatic Camera Calibration ◽  
Calibration Techniques

We present a web service for image based 3D reconstruction. The system allows a cultural heritage professional to easily create a 3D model of a scene or object out of images taken from different viewpoints. The user uploads the images to our server on which all processing takes place, and the final result can be downloaded upon completion. Any consumer-class digital camera can be used, and the system is free to use for non-commercial purposes. The service includes a number of innovations to greatly simplify the process of taking pictures suitable for reconstruction. In particular, we are able to construct models of planar scenes and from photographs shot using a turntable, and at varying zoom levels. Although the first two may seem like particularly simple cases, they cause some mathematical issues with traditional self-calibration techniques. We handle these cases by taking advantage of a new automatic camera calibration method that uses meta-data stored with the images. For fixed-lens camera setups, we can also reuse previously computed calibrations to support otherwise degenerate scenes. Furthermore, we can automatically compute the relative scale and transformation between two reconstructions of the same scene, merging two reconstructions into one. We demonstrate the capabilities of the system by two case studies: turntable reconstruction of various objects and the reconstruction of a cave, with walls and roof integrated into a complete model.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Image registration with a computer driven S.T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 98-99
Author(s):  
A.M.H. Schepman ◽  
J.A.P. van der Voort ◽  
J.E. Mellema
Keyword(s):  
Spot Size ◽  
Scanning Transmission Electron Microscope ◽  
Small Computer ◽  
Structural Studies ◽  
Area Of Interest ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Specimen Area ◽  
On Line ◽  
Minimum Distances

A Scanning Transmission Electron Microscope (STEM) was coupled to a small computer. The system (see Fig. 1) has been built using a Philips EM400, equipped with a scanning attachment and a DEC PDP11/34 computer with 34K memory. The gun (Fig. 2) consists of a continuously renewed tip of radius 0.2 to 0.4 μm of a tungsten wire heated just below its melting point by a focussed laser beam (1). On-line operation procedures were developped aiming at the reduction of the amount of radiation of the specimen area of interest, while selecting the various imaging parameters and upon registration of the information content. Whereas the theoretical limiting spot size is 0.75 nm (2), routine resolution checks showed minimum distances in the order 1.2 to 1.5 nm between corresponding intensity maxima in successive scans. This value is sufficient for structural studies of regular biological material to test the performance of STEM over high resolution CTEM.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

Software pattern recognition applied to nanodiffraction patterns from a STEM instrument

1986 ◽  
Vol 44 ◽  
pp. 694-695
Author(s):  
G.Y. Fan ◽  
J.M. Cowley
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
Computer Software ◽  
Processing System ◽  
Light Level ◽  
Host Computer ◽  
Low Light ◽  
Image Processing System ◽  
Recent Developments ◽  
On Line

In recent developments, the ASU HB5 has been modified so that the timing, positioning, and scanning of the finely focused electron probe can be entirely controlled by a host computer. This made the asynchronized handshake possible between the HB5 STEM and the image processing system which consists of host computer (PDP 11/34), DeAnza image processor (IP 5000) which is interfaced with a low-light level TV camera, array processor (AP 400) and various peripheral devices. This greatly facilitates the pattern recognition technique initiated by Monosmith and Cowley. Software called NANHB5 is under development which, instead of employing a set of photo-diodes to detect strong spots on a TV screen, uses various software techniques including on-line fast Fourier transform (FFT) to recognize patterns of greater complexity, taking advantage of the sophistication of our image processing system and the flexibility of computer software.

Thickness Measurement in the AEM by Macintosh-Based Analysis of Two-Beam Convergent Beam Patterns

1990 ◽  
Vol 48 (2) ◽  
pp. 504-505
Author(s):  
John F. Mansfield ◽  
Douglas C. Crawford
Keyword(s):  
Electron Microscope ◽  
Video Camera ◽  
Thickness Measurement ◽  
Specimen Thickness ◽  
Crystalline Materials ◽  
Beam Dynamic ◽  
Line Measurement ◽  
On Line ◽  
Image Position ◽  
Convergent Beam

A method has been developed that allows on-line measurement of the thickness of crystalline materials in the analytical electron microscope. Two-beam convergent beam electron diffraction (CBED) patterns are digitized from a JEOL 2000FX electron microscope into an Apple Macintosh II microcomputer via a Gatan #673 CCD Video Camera and an Imaging Systems Technology Video 1000 frame-capture board. It is necessary to know the lattice parameters of the sample since measurements are made of the spacing of the diffraction discs in order to calibrate the pattern. The sample thickness is calculated from measurements of the spacings of the fringes that are seen in the diffraction discs. This technique was pioneered by Kelly et al, who used the two-beam dynamic theory of MacGillavry relate the deviation parameter (Si) of the ith fringe from the exact Bragg condition to the specimen thickness (t) with the equation:Where ξg, is the extinction distance for that reflection and ni is an integer.

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