Zhen-qing ZHAO, Dong* YE, Xin ZHANG, et al. Calibration of area-array camera parameters based on improved exact measuring angle method[J]. Optics and precision engineering, 2016, 24(7): 1592-1599.
DOI:
Zhen-qing ZHAO, Dong* YE, Xin ZHANG, et al. Calibration of area-array camera parameters based on improved exact measuring angle method[J]. Optics and precision engineering, 2016, 24(7): 1592-1599. DOI: 10.3788/OPE.20162407.1592.
Calibration of area-array camera parameters based on improved exact measuring angle method
An improved exact measuring angle algorithm is proposed for parameter calibration of area array cameras. Based on a given estimated principal point of camera
the algorithm calculated deviation between the estimated and actual principal points and focal distance of the camera by using the corresponding relationship between intersection angle of two beams of parallel lights and image point of projection on the camera. The influence of image feature extraction error on intersection angle measurement accuracy of parallel lights was analyzed and an optimal estimation based on the minimum intersection angle error of parallel lights was employed so as to promote the calibration accuracy of internal parameter of the camera. Simulation experiment was conducted to analyze the influence of image feature extraction accuracy and intersection angle measurement accuracy of parallel lights on camera parameter calibration precision. The results show that the calibration accuracies of principal point and focal distance can reach 0.56 pixel and 0.06 mm respectively when image characteristics extraction accuracy is 0.1 pixel and two-dimensional rotary table accuracy is 0.5". An two-dimensional rotary table with accuracy reaching 0.5" is used for parameter calibration of the camera. In comparison of intersection angle error of parallel light calculated based on image point and calibration results with the calibration result
the error of the improved algorithm is 68.6% of the classic exact measuring angle method. This proves that the proposed algorithm has a better accuracy in parameter calibration of area array camera.
LIU SH G, JIANG ZH ZH, DONG Y H, et al.. Sub-regional camera calibration based on moving light target[J]. Opt. Precision Eng., 2014, 22(2):259-265.(in Chinese)
YE F, WANG M, CHEN J D, et al.. Camera nonlinear distortion correction based on coplanar points[J]. Opt. Precision Eng., 2015, 23(10):1962-1970.(in Chinese)
ZHU W D, CAO L H, MEI B, et al.. Calibration of industrial cameras using asymmetric circle center projection[J]. Opt. Precision Eng., 2014, 22(8):2267-2273.(in Chinese)
HUANG F SH, QIAN H F. Camera calibration technology driven by three-coordinate measuring machine[J]. Opt. Precision Eng., 2010, 18(4):952-957.(in Chinese)
WANG Z CH, DAI M, LI G, et al.. Calibration and analysis of line-scan camera based on virtual stereo pattern[J]. Infrared and Laser Engineering, 2014, 43(3):902-907.(in Chinese)
WU G D, HAN B, HE X. Calibration of geometric parameters of line-array CCD camera based on exact measuring angle in lab[J]. Opt. Precision Eng., 2007, 15(10):1628-1632.(in Chinese)
LIU W Y, JIA J Q, DING Y L, et al.. Measurement error impact on intrinsic parameters calibration in precise angle measurement method[J]. Infrared and Laser Engineering, 2009, 38(4):705-709.(in Chinese)
LIU W Y, DING Y L, JIA J Q. Factor analysis for impactions on principal point accuracy in exact measuring angle method[C].International Symposium on Photonics and Optoelectronics, Chengdu, China, 2010.
LIU B, JIA J Q, DING Y L. Geometric calibration with angle measure for CCD aerial photogram metric camera in laboratory[J]. Laser & Infrared, 2010, 40(3):298-301.(in Chinese)
LIU W Y, DING Y L, JIA J Q, et al.. Calibration of inner orientation elements for camera by means of star points[J]. Opt. Precision Eng., 2010, 18(9):2086-2093.(in Chinese)
YUAN G Q, DING Y L, HUI SH W, et al.. Grouped approach algorithm for mapping camera calibration based on method of exact measuring angle[J]. Acta Optica Sinica, 2012, 32(1):0112005.(in Chinese)
RYUSUKE S, YASUSHI Y. Accurate calibration of intrinsic camera parameters by observing parallel light pairs[C].International Conference on Robotics and Automation, Pasadena, CA, USA, 2008:1390-1397.
YAO ZH J, HAN Q L. Laser radiation accuracy measurement system of moving target in laser guidance[J]. Chinese Journal of Liquid Crystals and Displays, 2014, 29(6):1124-1130.(in Chinese)
ZHAO J X, ZHOU F Q. High precision center location algorithm of small scale focal spot[J]. Infrared and Laser Engineering, 2014, 43(8):2690-2693.(in Chinese)
WANG L B, WANG Y J, DI N, et al.. Subpixel location of circle target center based on geometric features[J]. Chinese Journal of Liquid Crystals and Displays, 2014, 29(6):1003-1009.(in Chinese)