关于利用OCR识别图形验证码

tiger吴

import tesserocr
from PIL import Image

image=Image.open('code.jpg')
result=tesserocr.file_to_text(image)
print(result)

Traceback (most recent call last):
  File "C:/Users/50519/PycharmProjects/untitled/test.py", line 5, in <module>
    result=tesserocr.file_to_text(image)
  File "tesserocr.pyx", line 2471, in tesserocr._tesserocr.file_to_text
  File "tesserocr.pyx", line 43, in tesserocr._tesserocr._b
TypeError: Expected bytes, got JpegImageFile

Process finished with exit code 1

验证码地址：http://my.cnki.net/elibregister/CheckCode.aspx
这是什么问题，怎么解决？