notebook demo error.

[piperod]

When running cell, this fragment is generating an error:
``
InvalidArgumentError: Expected image (JPEG, PNG, or GIF), got unknown format starting with 'II*\000\010\000\000\000\033\000\376\000\004\000\001\000'
[[{{node DecodeJpeg}}]] [Op:IteratorGetNextSync]

During handling of the above exception, another exception occurred:

NameError Traceback (most recent call last)
in ()
32 except InvalidArgumentError as e:
33 invalid_flag = 0
---> 34 for j, fname in enumerate(filenames):
35 fname = fname.numpy().decode('utf-8')
36 if os.path.isfile(fname):
``
NameError: name 'filenames' is not defined : JPEG, PNG, or GIF.

It seems .tiff is generating the error, should we convert the images to formats?