Python 从图像pytesser中提取文本失败

文本提取问题。我不熟悉在python中使用图像提取

from pytesser import *
import Image 

file = 'C:\\Image1.bmp'
image = Image.open(file)  # Open image object using PIL
print "1",image_to_string(image)     # Run tesseract.exe on image
print "2",image_file_to_string(file)

Text extraction works on Image1.
>> Text

Text extract does NOT work on Image2.
>> C)

请给我一些建议。