cnn-captcha/conf/captcha_config.json

{
  "root_dir": "sample/origin/",
  "image_suffix": "png",
  "characters": "0123456789abcdefghijklmnopqrstuvwxyz",
  "count": 20000,
  "char_count": 4,
  "width": 100,
  "height": 60,
  "webserver_captcha_url": "127.0.0.1",
  "webserver_captcha_port": 6100
}