https://www.cnblogs.com/wj-1314/p/9454656.html
https://www.cnblogs.com/pejsidney/p/9487881.html
https://digi.bib.uni-mannheim.de/tesseract/
https://blog.csdn.net/qq_40147863/article/details/82290015
https://blog.csdn.net/boonya/article/details/81325997
合并字库 https://www.cnblogs.com/c2soft/articles/10415236.html
完整教程 https://www.cnblogs.com/wpcnblog/p/12850590.html