Wen-tao LI, Pei-jun WANG, Xiao-min TANG. Accurate and rapid contour extraction of visual measurement for rail wear[J]. Optics and precision engineering, 2018, 26(1): 238-244.
DOI:
Wen-tao LI, Pei-jun WANG, Xiao-min TANG. Accurate and rapid contour extraction of visual measurement for rail wear[J]. Optics and precision engineering, 2018, 26(1): 238-244. DOI: 10.3788/OPE.20182601.0238.
Accurate and rapid contour extraction of visual measurement for rail wear
In order to ensure the high precision of dynamic visual measurement of rail abrasion
image acquisition and image processing technology were used to get clear light-stripe image and extract the sub-pixel coordinates of the light-stripe accurately. First
according to the high contrast between the light-stripe and the background brightness
a method of automatic exposure of the camera based on the brightness of the light-stripe was proposed
which could ensure a clear image of the light-stripe. Then the dynamic threshold segmentation method was presented to extract the light-stripe preliminarily according to the lightness decay feature of the light-stripe in the normal direction
this method can filter out the background of the image while preserving the normal attenuation of light. Finally
according to the overexposure information of the image to determine the approximate position of the center point of the light-stripe
then the Hessian matrix was calculated for the corresponding pixel position of the segmented image to obtain the sub-pixel coordinates of the light-stripe. Using MFC to write application for testing
under different illumination and background interference
this method can accurately extract the center of light-stripe
the extraction accuracy is 0.05 pixel and the computation time is reduced by 40% compared with the classical Steger algorithm. Experimental results show that the proposed method has good stability and strong anti-interference ability
can meet the requirements of the rail abrasion measurement.
ZHAN D, YU L, XIAO J, et al .. Study on high-accuracy vision measurement approach for dynamic inspection of full cross-sectional rail profile[J]. Journal of the China Railway Society , 2015, 37(9):96-106. (in Chinese)
KANG G Q, LI CH M, QIN L J, et al .. Research on a method of calibrating dynamic rail profile data[J]. Chinese Journal of Sensors and Actuators , 2015, 28(2):221-226. (in Chinese)
HUA CH Q, KOU D H, FU SH L, et al .. Approach comparison of several rail wear instrumentation and measurements[J]. Chinese Railways , 2013(4):67-70. (in Chinese)
WANG X H, WAN Y, LI R, et al .. A multi-object image segmentation C-V model based on region division and gradient guide[J]. Journal of Visual Communication and Image Representation , 2016, 39:100-106.
CHEN K, CHEN F, DAI M, et al .. Fast image segmentation with multilevel threshold of two-dimensional entropy based on firefly algorithm[J]. Opt. Precision Eng ., 2014, 22(2):517-523. (in Chinese)
HARUKI T, KIKUCHI K. Video camera system using fuzzy logic[J]. IEEE Transactions on Consumer Electronics , 1992, 38(3):624-634.
YANG H T, CHANG Y L, WANG J, et al .. A new automatic exposure algorithm for video cameras using luminance histogram[J]. Acta Optica Sinica , 2007, 27(5):841-847. (in Chinese)
LI F J, LI X J, LIU ZH. A multi-scale analysis based method for extracting coordinates of laser light stripe centers[J]. Acta Optica Sinica , 2014, 34(11):1110002. (in Chinese)
STEGER C. An unbiased detector of curvilinear structures[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence , 1998, 20(2):113-125.
SUN J H, WANG H, LIU ZH, et al .. Rapid extraction algorithm of laser stripe center in rail wear dynamic measurement[J]. Opt. Precision Eng ., 2011, 19(3):690-696. (in Chinese)
JIA Q Q, WANG B X, LUO X ZH. Extraction of central positions of light stripe in sub-pixel in 3D surface measurement based on light sectioning method[J]. Opt. Precision Eng ., 2010, 18(2):390-396. (in Chinese)
People's Republic of China Ministry of Railways. Maintenance Rules for Ballasted Track High-speed Railway Track ( Trial )[M]. Beijing:China Railway Publishing House, 2013. (in Chinese)