求助。使用PIL的ImageEnhance

enh.enhance(1.3)后出现
Traceback (most recent call last):
File "<pyshell#192>", line 1, in <module>
enh.enhance((1.3))
File "C:\Python27\lib\site-packages\PIL\ImageEnhance.py", line 36, in enhance
return Image.blend(self.degenerate, self.image, factor)
File "C:\Python27\lib\site-packages\PIL\Image.py", line 2008, in blend
return im1._new(core.blend(im1.im, im2.im, alpha))
TypeError: must be ImagingCore, not ImagingCore