Development of Levelling Staff Scale Calibration Method by Integrating a CCD Camera

2021 ◽  
pp. 514-521
Author(s):  
Sergej Baričević ◽  
Đuro Barković ◽  
Mladen Zrinjski ◽  
Tomislav Staroveški
Keyword(s):  
Ccd Camera ◽  
Calibration Method ◽  
Scale Calibration

CCD Camera Calibration Technology Based on the Translation of Coordinate Measuring Machine

2014 ◽  
Vol 568-570 ◽  
pp. 320-325 ◽  
Author(s):  
Feng Shan Huang ◽  
Li Chen
Keyword(s):  
Coordinate System ◽  
Camera Calibration ◽  
Characteristic Point ◽  
Coordinate Measuring Machine ◽  
Ccd Camera ◽  
Mathematic Model ◽  
Calibration Method ◽  
Calibration Characteristic ◽  
Standard Sphere ◽  
Measuring Machine

A new CCD camera calibration method based on the translation of Coordinate Measuring Machine (CMM) is proposed. The CMM brings the CCD camera to produce the relative translation with respect to the center of the white ceramic standard sphere along the X, Y, Z axis, and the coordinates of the different positions of the calibration characteristic point in the probe coordinate system can be generated. Meanwhile, the camera captures the image of the white ceramic standard sphere at every position, and the coordinates of the calibration characteristic point in the computer frame coordinate system can be registered. The calibration mathematic model was established, and the calibration steps were given and the calibration system was set up. The comparing calibration result shows that precision of this method is equivalent to that of the special calibration method, and the difference between the calibrating data of these two methods is within ±1μm.

Camera Calibration Method Based on Halcon

2013 ◽  
Vol 385-386 ◽  
pp. 518-522
Author(s):  
Zhi Xian Zhang ◽  
Li Liang ◽  
Yong Deng
Keyword(s):  
Computer Vision ◽  
Camera Calibration ◽  
Ccd Camera ◽  
Calibration Method ◽  
Geometrical Model ◽  
Accuracy Analysis ◽  
Calibration Algorithm ◽  
Cross Platform ◽  
Computation Speed

Aiming at the applications of computer vision,a nonlinear image geometrical model for array CCD camera was build and the interior parameters and exterior parameters as well were analyzed.By applying Halcon calibration board with circular targets plane of matrix gridding type and functions library,a camera calibration algorithm and accuracy analysis were given.Experiments indicated that the parameters were accurate and this method is simple and it improves the calibration precision and computation speed, and has a good cross-platform portability.

A novel calibration method of CCD camera for LAMOST

2012 ◽  
Author(s):  
Yonggang Gu ◽  
Yi Jin ◽  
Chao Zhai
Keyword(s):  
Ccd Camera ◽  
Calibration Method

scholarly journals Fluoroscopy-based laser projection system for surgical guidance and its calibration methods

10.29007/m1cq ◽  
2018 ◽  
Author(s):  
Sanghyun Joung ◽  
Hyunwoo Lee ◽  
Chul-Woo Park ◽  
Chnag-Wug Oh ◽  
Il-Hyung Park
Keyword(s):  
Experimental System ◽  
Ccd Camera ◽  
Calibration Method ◽  
Optical Tracking ◽  
Angular Error ◽  
Measurement Unit ◽  
Projection System ◽  
Calibration Phantom ◽  
Calibration Methods ◽  
Laser Module

We have developed a laser projection system, which can project laser on corresponding position to surgical planning drawn at a fluoroscopic image without an optical tracking system. In this paper, we introduce a spatial calibration method between a laser module and a fluoroscope for the laser projection and evaluate its accuracy with a mimic experimental system. The experimental system consists of a laser module, a distance measurement unit and a CCD camera. The laser modules can project arbitrary line on surface by reflecting a point source laser with two galvanometers. We designed a calibration phantom by combining a collimator for accurate laser pattern positioning and stainless steel ball arrays for calculation of an extrinsic parameter of a C-arm fluoroscopy. We set a projection plane having ruler in 400mm distance from the CCD camera, and set 54 points on the screen. The laser module projects points with respect to the set points, and a distance error between set points and projected points and angular error are calculated. The distance errors is 1.5±1.9 mm (average ± standard deviation). Maximum error was 7.5 mm. Angular error was smaller than 2 degrees. The laser projection system and its calibration method shows clinically acceptable accuracy and the clinical application is the next step.

A Camera Calibration Method Based on Free Points

2011 ◽  
Vol 130-134 ◽  
pp. 1885-1888
Author(s):  
Jing Lei Zhang ◽  
Kai Bo Fan ◽  
Yan Jiao Wang
Keyword(s):  
Standard Deviation ◽  
Ccd Camera ◽  
Least Square Method ◽  
Calibration Method ◽  
Initial Guess ◽  
Least Square ◽  
Camera Model ◽  
Extrinsic Parameters ◽  
The Mean ◽  
Constraint Method

A new accurate calibrating technique for intrinsic parameters and extrinsic parameters of CCD camera is described. The camera model is derived by the pinhole projection theory. Then other parameters of the model are resolved under the radial alignment constraints and orthogonal constraints. In order to get a fine initial guess for the nonlinear searching solution, the least square method is introduced, and finally uses radial alignment constraint method to get the results. The experimental results show that the mean absolute differences in x direction and y direction are 0.0070 and 0.1430 separately while the standard deviation are 0.5006 and 1.2046 separately.

scholarly journals Automatic Laser Interferometer And Vision Measurement System For Stripe Rod Calibration

2015 ◽  
Vol 22 (4) ◽  
pp. 491-502 ◽  
Author(s):  
Min Zhao ◽  
Qiu-Hong Huang ◽  
Ling-Jian Zhu ◽  
Zong-Ming Qiu
Keyword(s):  
Measurement System ◽  
Measurement Method ◽  
Laser Interferometer ◽  
Image Data ◽  
Ccd Camera ◽  
Calibration Method ◽  
Feedback Signal ◽  
Long Distance ◽  
Loop Control ◽  
Vision Measurement

Abstract In order to calibrate the stripe precision of a leveling rod, an automatic laser interferometer and a vision measurement system were designed by Xi’an University of Technology in China. The rod was driven by a closed-loop control and the data were collected at the stop state to ensure precision. The laser interferometer provided not only the long distance data but also a position feedback signal in the automatic control loop. CCD camera and a vision measurement method were used to inspect the stripe edge position and defect. A pixel-equivalent self-calibration method was designed to improve precision. ROI (regions of interest) method and an outline tracing method were designed to quickly extract multiple stripe edges. A combination of the image data with the interferometer data reduces control difficulty and ensures the measurement accuracy. The vision measurement method reached sub-pixel precision and the defective edges were reported. The system can automatically calibrate a stripe leveling rod with a high degree of efficiency and precision.

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