Saving TIFF as JPEG causes malformed image

[gverm]

What did you do?

Tried saving TIFF as JPEG.

What did you expect to happen?

JPEG to look the same as TIFF.

What actually happened?

Save exits successfully, but image looks malformed.

What are your OS, Python and Pillow versions?

• OS: EndeavourOS/Alpine Linux
• Python: 3.10/3.11
• Pillow: 9.5.0

from PIL import Image
src_img = Image.open("e7fe2857104360d68e6b7c51f9f0a5a5-MA_ROM_VII_FO_0069.tif")
dst_img = src_img.convert("RGB")
dst_img.save("test.jpg", quality=95)

Original image
converted JPEG

The mode of the original TIFF is I;16 and I've read that this is only partially supported. I've tried looking through the issues to see if I could find a reason why this doesn't work and it seems #1888 might be related, but I'm not sure.

EDIT: forgot to mention, using OpenCV to convert works correctly.

[radarhere]

#3159 is the relevant open issue.

If you're looking for an immediate solution, I can offer the following code.

from PIL import Image
src_img = Image.open("e7fe2857104360d68e6b7c51f9f0a5a5-MA_ROM_VII_FO_0069.tif")
if src_img.mode == "I;16":
	src_img = src_img.point(lambda i: i * (1 / 255))
dst_img = src_img.convert("RGB")
dst_img.save("test.jpg", quality=95)

[gverm]

Thanks @radarhere that works. I'll close this as a duplicate of #3159 then.