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Defects Length Measurement Using an Estimation Agorithm of the Camera Orientation and an Inclination Angle of a Laser Slit Beam

레이저 슬릿 빔의 경사각과 카메라 자세 추정 알고리듬을 이용한 벽면결함 길이측정

  • Published : 2002.01.01

Abstract

A method of measuring the length of defects on the wall and restructuring the defect image is proposed based on the estimation algorithm of a camera orientation, which uses the declination angle of a laser slit beam. The estimation algorithm of the horizontally inclined angle of CCD camera adopts a 3-dimensional coordinate transformation of the image plane where both the laser beam and the original image of the defects exist. The estimation equation is obtained by using the information of the beam projected on the wall and the parameters of this equation are experimentally obtained. With this algorithm, the original image of the defect can be reconstructed as an image normal to the wall. From the result of a series of experiments, the measuring accuracy of the defect is measured within 0.5% error bound of real defect size under 30 degree of the horizontally inclined angle. The proposed algorithm provides the method of reconstructing the image taken at any arbitrary horizontally inclined angle as the image normal as the wall and thus, it enables the accurate measurement of the defect lengths by using a single camera and a laser slit beam.

Keywords

References

  1. Vittorio Murino and Andrea Trucco, 'A confidence based approach to enhancing underwater acoustic image formation,' IEEE Transactions on Image Processing, vol. 8, no. 2, pp. 270-285, 1999 https://doi.org/10.1109/83.743860
  2. Stephen Tetlow and John Spours, 'Three dimensional measurement of underwater work sites using structured laser light,' Meas. Sci. Technol., vol. 10, pp. 1162-1167, 1999 https://doi.org/10.1088/0957-0233/10/12/307
  3. Chisato Kanamori, Makoto Kautani, and Tadashi Marauds, 'A coordinate measuring method using laser plane scanners(2nd Report),' 情密工學會誌(日本), vol. 63, no. 1. pp. 119-216, 1997
  4. Kuntal Sengupta and Liyanage C. DeSilva, 'A new depth cue based algorithm for back-ground, fore-ground segmentation,' SPIE, vol. 3653, pp. 1305-1314, 1999 https://doi.org/10.1117/12.334639
  5. Woontack Woo and Antonio Ortega, 'Modified overlapped block disparity compensation for stereo image coding,' SPIE, vol. 3653, pp. 570-581, 1999 https://doi.org/10.1117/12.334707
  6. R. S. Petty, M. Robinson, and J. P. O. Evans, '3D measurement using rotating line-scan sensors,' Meas. Sci. Technol. vol. 9, pp. 339-346, 1998 https://doi.org/10.1088/0957-0233/9/3/005
  7. Toshiyuki Takatsuji, Atsushi Kirita, and Tomizo Kurosawa, 'A simple instrument for measuring edge angles using a light sectioning method,' Meas. Sci. Technol., vol. 9, pp. 782-786, 1997 https://doi.org/10.1088/0957-0233/8/7/013
  8. Tom Rezenik, 'Tutorial : In-line laser measurement in the assembly process,' Industrial Robot, vol. 24, no. 1, pp. 16-23, 1997 https://doi.org/10.1108/01439919710162610
  9. Yong-Hui Fa and Yoel Moalem, 'Effective defect detection and classification methodology based on integrated laser scanning inspection and automatic defect classification,' IEEE/ SEMI Advanced Smiconductor Manufacturing Conference, pp. 266-271, 1998 https://doi.org/10.1109/ASMC.1998.731570
  10. Prabir Bhattacharya, Kai Qian, Siqi Cao, and Yi Qian, 'Skeletonization with hollow detection on gray image by gray weighted distance transform,' SPIE, vol. 3460, pp. 746-754, 1998 https://doi.org/10.1117/12.323232
  11. N. C. Krieger and Lassen, 'Automatic localization of electron back-scattering pattern bands from hough transform,' Materials Science and Technology, vol. 12, pp. 837-843, October, 1996 https://doi.org/10.1179/mst.1996.12.10.837
  12. James Clark, Emanuele Trucco, and Lawrence B. Wolff, 'Using light polarization in laser scanning,' Image and Vision Computing, vol. 15, pp. 107-117, 1997 https://doi.org/10.1016/S0262-8856(96)01126-2