TY - GEN
T1 - Automated surface profile measurement of printed circuit boards by phase-shifted shadow moiré
AU - Chen, T. Y.
AU - Lin, J.
N1 - Funding Information:
This work is supported by National Science Council, Republic of China under the contract no. NSC-101-2221-E-006-101.
PY - 2014
Y1 - 2014
N2 - Phass-shifted shadow Moire has gained more applications in electronic industry. However, printed circuit boards (PCB) may contain many cavities or specular materials on the surface that make the phase-unwrapping of Moire fringe patterns more difficult or fail. In this paper, a method is proposed to overcome this difficulty to process the phase-shifted fringe patterns effectively and automatically for surface profile measurement. Firstly the intensity values of the original four phase-shifted fringe patterns are averaged and differentiated to enhance the erroneous spots. Then the median grey-level value of the enhanced image is used as the threshold to binarize the enhanced image to find the erroneous bright and black spots. According to the largest size of erroneous spot, the size of a structuring element is determined for morphology filtering. Thereafter the phase can be calculated and unwrapped correctly. Test of the method on a PCB is demonstrated and discussed.
AB - Phass-shifted shadow Moire has gained more applications in electronic industry. However, printed circuit boards (PCB) may contain many cavities or specular materials on the surface that make the phase-unwrapping of Moire fringe patterns more difficult or fail. In this paper, a method is proposed to overcome this difficulty to process the phase-shifted fringe patterns effectively and automatically for surface profile measurement. Firstly the intensity values of the original four phase-shifted fringe patterns are averaged and differentiated to enhance the erroneous spots. Then the median grey-level value of the enhanced image is used as the threshold to binarize the enhanced image to find the erroneous bright and black spots. According to the largest size of erroneous spot, the size of a structuring element is determined for morphology filtering. Thereafter the phase can be calculated and unwrapped correctly. Test of the method on a PCB is demonstrated and discussed.
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U2 - 10.1007/978-3-319-00768-7_30
DO - 10.1007/978-3-319-00768-7_30
M3 - Conference contribution
AN - SCOPUS:84886739855
SN - 9783319007670
T3 - Conference Proceedings of the Society for Experimental Mechanics Series
SP - 235
EP - 240
BT - Advancement of Optical Methods in Experimental Mechanics - Conference Proceedings of the Society for Experimental Mechanics Series
T2 - 2013 Annual Conference on Experimental and Applied Mechanics
Y2 - 3 June 2013 through 5 June 2013
ER -