gif file is not supported

[Adrian Belen]

I tried to embed a string into an image however this error occurs.
looks like image function problem

Traceback (most recent call last):
  File "testlsb.py", line 74, in <module>
    main()
  File "testlsb.py", line 25, in main
    steg = LSBSteg.LSBSteg(cv2.imread(inputImg))
  File "/app/stargazer/LSBSteganography/LSBSteg.py", line 29, in __init__
    self.height, self.width, self.nbchannels = im.shape
AttributeError: 'NoneType' object has no attribute 'shape'