1. Zhu Q B and Zhang T Y. 2014. Digital evaluation method and application of metallic materials grain size. Heat Treatment of Metals. 39, (Sep. 2014), 132--136. doi:10.13251/j.issn. 0254--6051.2014.09.035.
2. Liu S K, Wang J F, Si S G, Li J F and Han J T. 2008. Recognition and edge-extraction of grain boundary in materials' microstructure. Chinese Journal of Stereology and Image Analysis. 13, (Jun. 2008), 134--137. doi: 10.13505/j.1007-1482.2008.02.006.
3. Li X C, Zhao C G, Zhu W X, Ma Z J, Zhuang Z P and Zhang Y. 2013. Restoring method of metallographic image of ultra-fine grain steel based on water-growing. Transactions of Materials and Heat Treatment. 34, (Sep. 2013), 69--73. doi: 10.13289/j.issn.1009-6264.2013.09.001.
4. Zhao X X, Jin W Y, Qi X L and Xie J T. 2013. Application of improved Canny algorithm in investigation of GCr15 bearing steel metallographic image. Hot Working Technology. 42, (Sep. 2013), 211--213. doi:10.14158/j.cnki.1001-3814.2013.18.005.
5. Xue W H, Wang H, Liu G Q, Feng M N, Qi L and Chen Z P. 2015. Segmentation method of grain microstructure based on similarity among image sequence. Chinese Journal of Stereology and Image Analysis. 20, (Dec. 2015), 400--407. doi:10.13505/j.1007-1482.2015.20.04.012.