验证码报错

[BeyondHeaven]

crd@crd-PC:~/Desktop/ccgp_crack/PythonSpiderNotes/Captcha1$ python tess_test.py PNG (200, 70) 1 Traceback (most recent call last): File "tess_test.py", line 224, in filter_enhance(midu_image_name, midu_image_name_pro1) File "tess_test.py", line 91, in filter_enhance im = enhancer.enhance(2) File "/usr/local/lib/python2.7/dist-packages/PIL/ImageEnhance.py", line 37, in enhance return Image.blend(self.degenerate, self.image, factor) File "/usr/local/lib/python2.7/dist-packages/PIL/Image.py", line 2631, in blend return im1._new(core.blend(im1.im, im2.im, alpha)) ValueError: image has wrong mode

请问这是怎么回事？谢谢