What did you do?

Opened a bitonal TIFF created with Adobe Photoshop CC (version 20.0.2) then saved it with Group4 compression using Pillow.

TIFF Image should be downloadable from Github repository here: https://github.com/photosbyjeremy/images/blob/master/test_bitonal_text.tif.zip

What did you expect to happen?

I expected the image to save with compression.

What actually happened?

In Pillow 5.4.1 there was a Segmentation Fault 11, but in Pillow 5.3.0 it works just fine.

What are your OS, Python and Pillow versions?

• OS: macOS 10.14.3
• Python: 3.6.8 (and I actually tried 3.7.1 first, but didn't screenshot those attempts)
• Pillow: 5.4.1 and 5.3.0

Please include code that reproduces the issue and whenever possible, an image that demonstrates the issue. Please upload images to GitHub, not to third-party file hosting sites. If necessary, add the image to a zip or tar archive.

The best reproductions are self-contained scripts with minimal dependencies. If you are using a framework such as plone, Django, or buildout, try to replicate the issue just using Pillow.

from PIL import Image
image = Image.open('test_bitonal_text.tif')
image.save('test_pillow_save.tif', compression='group4')