对单数字的验证码，通过一些OCR引擎，如：tesseract，AspriseOCR很容易解决问题。但碰到如CSDN论坛这中图形验证码就比较麻烦，必须先通过预处理。使图象二值化，黑白灰度，增加亮度。-The single digit verification code, through the OCR engine, such as: Tesseract, AspriseOCR very easy to solve the problem. But the encounter such as CS