A fast pruning algorithm based on endpoints tracing is proposed to solve the problem that the branches of the linear structured light stripe skeleton lead to the un-smoothness of the stripe center. The algorithm is based on the skeleton extraction in mathematical morphology
and the pruning theory and the realization process are given. The algorithm removes branches of the skeleton by recognizing and removing endpoints along branch directions without establishing a tracing rule to judge branch directions. The tracing length is determined by the branch length instead of a given fixed threshold
thus the pruning efficiency is improved. Experimental results show that there is a linear relationship between the pruning time of the algorithm and the total length of branches. Comparison with the traditional pruning algorithm shows that the pruning speed of the proposed algorithm is improved by three to seven times
and that the algorithm cuts down branches effectively and retains the skeleton trunk. This algorithm realizes the fast pruning of the fairing and unidirectionalby connected skeletons
and improves the speed and accuracy of the 3D measurement.
关键词
Keywords
references
TIAN Qingguo, ZHANG Xiangyu, MA Qian, et al. Utilizing polygon segmentation technique to extract and optimize light stripe centerline in line-structured laser 3D scanner [J]. Pattern Recognition, 2016, 55(2): 100-113.
CUI Xijun, YANG Chuan, LIU Baohua, et al. Self adaptive iterative method of extracting center of linear structured light stripe [J]. Journal of Xi'an Jiaotong University, 2007, 41(1): 73-76.
ZHANG Weiguang, ZHAO Hong. Error correction method for three-dimensional measurement system with multi-sensor and linear-structure light [J]. Journal of Xi'an Jiaotong University, 2011, 45(6): 75-80.
JIA Qianqian, WANG Boxiong, LUO Xiuzhi. Extraction of central positions of light stripe in sub-pixel in 3D surface measurement based on light sectioning method [J]. Optics and Precision Engineering, 2010, 18(2): 390-396.
LI Fengjiao, LI Xiaojing, LIU Zhen. A multi-scale based method for extracting coordinates of laser light stripe centers [J]. Acta Optica Sinica, 2014, 34(11): 103-108.
WU Qingyang, SU Xianyu, SONG Fang. A pruning algorithm for the skeleton of line-structure-light pattern [J]. Journal of Sichuan University(Engineering Science Edition), 2006, 38(5): 148-151.
YU Haipeng, LIU Yixing, LIU Zhenbo. Auto detection of wood texture orientation by Radon transform [J]. Journal of Forestry Research, 2005, 16(1): 1-4.
ZHAO Shan, WANG Biao, TANG Chaoying. Arm vein feature extraction and matching based on chain code [J]. Acta Optica Sinica, 2016, 36(5): 1-12.
SHEN Wei, BAI Xiang, YANG Xingwei, et al. Skeleton pruning as trade-off between skeleton simplicity and reconstruction error [J]. Science China Information Sciences, 2013, 56(4): 1-14.
FATIMA J, SYED A M, AKRAM M U. Feature point validation for improved retina recognition [C]∥Proceedings of the 2013 IEEE Workshop on Biometric Measurements and Systems for Security and Medical Applications. Piscataway, NJ, USA: IEEE, 2013: 13-16.
LIU Wenxing, WANG Zhaoqi, MU Guoguang. Ridge tracing and application in post-processing of thinned fingerprints [J]. Journal of Optoelectronics•Laser, 2002, 13(2): 13-16.
OTSU N A. A threshold selection method from gray-level histograms [J]. IEEE Transactions on Systems, Man, and Cybernetics, 1979, 9(1): 62-66.