What did you do?

I try to Image.open(tiff_path) on a 8-bit tiff image and got an error.

What did you expect to happen?

Image.open() is supposed to work on a 8-bit tiff image.

What actually happened?

Error from Pillow

  File "test.py", line 3, in <module>
    page=Image.open(path)
  File "/tmp/tiff/venv/local/lib/python2.7/site-packages/PIL/Image.py", line 2622, in open
    % (filename if filename else fp))
IOError: cannot identify image file '/path/to/Sample.tiff'

What are your OS, Python and Pillow versions?

• OS: Debian 6.0
• Python: Python 2.7
• Pillow: Tried both legacy 2.9.0 and 5.2.0

from PIL import Image
path = "/Image/Sample.tiff"
page=Image.open(path)

The images are not public so I can't share them. But here are some imagemagick identify that may help.

Image that caused the error
Original image:

TIFF 3426x4378 3426x4378+0+0 1-bit Bilevel Gray 578044B 0.010u 0:00.009
unknown field with tag 32934 (0x80a6) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/704.

Processed image(resized without -strip)
TIFF 6669x6812 6669x6812+0+0 8-bit DirectClass 3.738MB 0.000u 0:00.000
A working image:
TIFF 5945x7399 5945x7399+0+0 8-bit DirectClass 4.952MB 0.000u 0:00.000

If there is any way to fix this image for Pillow loading, it would help as well.
Should unknown field with tag cause Pillow tiff loading issue?