Calibration of quad-camera measurement systems using a one-dimensional calibration object for three-dimensional point reconstruction

Li, Yunhui; Huo, Ju; Liu, Jia; Yang, Ming

doi:10.1117/1.oe.58.6.064107

Cited by 4 publications

(1 citation statement)

References 21 publications

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“…The conversion matrix T camB camA between the two camera coordinate systems and the conversion matrix T camA align between the camera A coordinate system and the alignment coordinate system can be obtained by prior calibration. By using the coordinates of the cooperation targets 1, 2 in the reference frame O − XY Z and their corresponding image plane coordinates, the rotation matrix R 1 and translation matrix t 1 from the reference frame to the alignment frame can be determined based on (5) and (6). From t 1 = (t x1 , t y1 , t z1 ) T , R 1 = R and t = −R 1 t 1 , the translation matrix t = (t x , t y , t z ) T from the upper alignment coordinate system to the bottom reference coordinate system can be obtained; subsequently, the horizontal alignment deviations t x and t y between the upper and lower parts can be determined.…”

Section: Model Of Position Measurementmentioning

confidence: 99%

Method for Horizontal Alignment Deviation Measurement Using Binocular Camera Without Common Target

Wang

Shen

et al. 2020

IEEE Access

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In the application of using binocular camera to measure the horizontal alignment deviation, due to the limited field of view of the camera, it is difficult for each camera to obtain all the target points to determine the position of the parts. To this end, a binocular position measurement model, where each optical camera corresponds to one cooperative target point, is established to determine the horizontal alignment deviation between the upper and lower parts. To overcome the problem of insufficient information in calculating the horizontal alignment deviation, the measurement data of a biaxial inclinometer and laser rangefinder are added. The Monte Carlo method is used to determine the error level for any position and attitude in the measurement range based on past work experience. The high accuracy of the position measurement method (the overall error does not exceed 2 mm) for a binocular camera without a common target meets the actual application requirements. This conclusion is verified by the experimental results. INDEX TERMS Binocular position measurement, horizontal alignment deviation, no common target, biaxial inclinometer, laser ranging, Monte Carlo method

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Section: Model Of Position Measurementmentioning

confidence: 99%

Method for Horizontal Alignment Deviation Measurement Using Binocular Camera Without Common Target

Wang

Shen

et al. 2020

IEEE Access

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Parallel optimization of tridimensional deformation measurement based on correlation function constraints of a multi-camera network

Gao¹,

Liang²,

Zhang³

et al. 2022

Appl. Opt.

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This study primarily investigates the low accuracy and redundant time-consuming problem of speckle registration in the full-field deformation measurement of slender and biggish specimens. To solve these problems, a parallel optimization of the tridimensional deformation measurement method is proposed based on what we believe is a novel correlation function constraints of a multi-camera network. First, a neotype correlation function is built based on the joint constraint relationship among the multiple cameras, which is capable of accurately restricting the search for homologous points in image pairs to the epipolar line, instead of the entire image, while significantly narrowing the search space and accelerating the search. The multiple cameras are bundled as a whole, thus reducing the dimension of the Jacobian matrix and the normalized matrix to a certain extent. Subsequently, more speckle images can be calculated in one iteration. Furthermore, the decomposition of the derived correlation function and the scheme of the parallel algorithm are decomposed via the kernel function based on the GPU parallel mechanism of the compute unified device architecture source program, thus increasing the subpixel search speed of speckle matching and ensuring the calculation performance of the stereo deformation measurement method to reach a higher level. Lastly, the experimental results revealed that the proposed strategy could allow the calculation speed-up ratio of speckle sequence and stereo registration to reach 20.390 times and 17.873 times, respectively, while ensuring the out-of-plane displacement average measuring accuracy to be higher than 0.179 mm within the spatial range of [2 m, 2 m, 3 m]. As a result, the proposed approach has crucial applications in rapid and stable tridimensional deformation measurement.

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Universal calibration for a ring camera array based on a rotational target

Wang

2022

Opt. Express

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Panoramic dynamic and static measurements of objects in the application of vision measurement are difficult due to the constraints of a camera field of view and multicamera calibration technology. This paper proposes a universal global calibration method for ring multicamera systems based on rotating target and multi-view vision technology. This method uses a rotating target to establish the relationship between ring multi-camera arrays, retrieves the coordinates of the target corners from the fields of view of different cameras, and combines them with the rotation angle to complete the coordinate unification of the system. The unification of coordinates is unaffected by the overlapping fields of view between cameras, and the number of cameras can be configured arbitrarily. The calibration accuracy, validity, and precision of the proposed method are verified through reprojection error, dynamic tensile test, and 3D reconstruction.

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Calibration of quad-camera measurement systems using a one-dimensional calibration object for three-dimensional point reconstruction

Cited by 4 publications

References 21 publications

Method for Horizontal Alignment Deviation Measurement Using Binocular Camera Without Common Target

Method for Horizontal Alignment Deviation Measurement Using Binocular Camera Without Common Target

Parallel optimization of tridimensional deformation measurement based on correlation function constraints of a multi-camera network

Universal calibration for a ring camera array based on a rotational target

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