[1] Zhang W J, Yang Y L, Li D et al. Key algorithms of automatic image measurement system[J]. Optics and Precision Engineering, 15, 294-301(2007).

[2] Liu T, Liu Y, Liu K et al. Intrusion object recognition and space distance measurement in safety area of high voltage transmission lines. [C]//2019 6th International Conference on Systems and Informatics (ICSAI), November 2-4, 2019, Shanghai, China. New York: IEEE, 878-883(2019).

[3] Barkavi T, Chidambarathanu N. Processing digital image for measurement of crack dimensions in concrete[J]. Civil Engineering Infrastructures Journal, 52, 11-22(2019). http://www.researchgate.net/publication/332142585_Processing_Digital_Image_for_Measurement_of_Crack_Dimensions_in_Concrete

[4] Song L M, Li D P, Qin M C et al. Research on high-precision hole measurement based on robot vision method[J]. Optoelectronics Letters, 10, 378-382(2014). http://www.opticsjournal.net/Articles/Abstract?aid=OJ171012000380Zv2y5B

[5] Duan Y X. Study on the measurement method of part size of automatic image measuring instrument[D]. Taiyuan: North University of China, 18-24(2019).

[6] Zheng Z, Zha B T, Xuchen Y S et al. Adaptive edge detection algorithm based on grey entropy theory and textural features[J]. IEEE Access, 7, 92943-92954(2019). http://ieeexplore.ieee.org/document/8758200

[7] Shang Y C, Chen J, Tian J W. Sub-pixel edge detection algorithm based on Gauss fitting[J]. Journal of Computer Applications, 31, 179-181(2011).

[8] Hua C J, Xiong X M, Chen Y. Feature extraction of workpiece circular arc contour based on sobel operator[J]. Laser & Optoelectronics Progress, 55, 021011(2018).

[9] Duan S L, Yin C C, Li D W. Improved adaptive Canny edge detection algorithm[J]. Computer Engineering and Design, 39, 1645-1652(2018).

[10] Shu Q L, Shan B[J]. Sub-pixel localization algorithm based on modified Canny operator Machinery Design & Manufacture, 2018, 165-168.

[11] Deng C X, Wang G B, Yang X R. Image edge detection algorithm based on improved Canny operator. [C]//2013 International Conference on Wavelet Analysis and Pattern Recognition, July 14-17, 2013, Tianjin, China. New York: IEEE, 168-172(2013).

[12] Yuan Q Q, Zhang G, Chen X J et al. Regularization of point cloud features by fusing improved canny algorithm[J]. Laser & Optoelectronics Progress, 56, 162801(2019).

[13] Ju Z Y, Zhang W X, Zhai C Y. Garbage image edge detection based on improved Canny algorithm[J]. Electronic Science and Technology, 33, 16-20(2020).

[14] Liang Z J, Zhong J. Adaptive Canny algorithm improvement based on Otsu algorithm and histogram analysis[J]. Modern Electronics Technique, 42, 54-58(2019).

[15] Rong W B, Li Z J, Zhang W et al. An improved Canny edge detection algorithm. [C]//2014 IEEE International Conference on Mechatronics and Automation, August 3-6, 2014, Tianjin, China. New York: IEEE, 577-582(2014).

[16] Chen X F, Guan H B, Gu J N et al[J]. improvements on Canny algorithm. Advanced Engineering Forum, 6/7, 205-209(2012).

[17] Liu L X, Li B W, Wang Y P et al. Remote sensing image segmentation based on improved Canny edge detection[J]. Computer Engineering and Applications, 55, 54-58, 180(2019).

[18] Xu H Y, Xu X L, Zuo Y B. Applying morphology to improve Canny operator's image segmentation method[J]. The Journal of Engineering, 2019, 8816-8819(2019).

[19] He Y B, Chen R L, Wu K et al. Point cloud simplification method based on K-means clustering[J]. Laser & Optoelectronics Progress, 56, 091002(2019).

[20] Xiong Z Y, Fan X P, Li Y. A new binary-area-morphology-based algorithm for license plate localization[J]. Computer Simulation, 25, 285-287, 296(2008).