ImageField doesn't consider EXIF rotation when storing width and height

[Adam]

When providing a height_field and width_field for an ImageField, it stores the dimensions, but without consideration of EXIF rotation. I have attached files to test with. The files ending with 5 through 8 all have their width and height swapped.

[Tim Graham]

Django simply uses ​Pillow to retrieve the dimensions, so this should be reproduced without Django and then (if a valid issue) reported there. A quick search revealed ​a possibly related issue.

If my analysis is incorrect, please reopen this ticket with an explanation of where Django is at fault.

[Adam]

Here is ​another Pillow issue that may be of interest. It seems that Pillow ignoring the EXIF orientation is by design. Pillow is used in various contexts, not just web. I think in other cases it may make sense to return the dimensions without considering the EXIF orientation. But the web defaults to considering the EXIF orientation (see ​this link). Since Django is for the web, I think it should consider the EXIF orientation. I was able to make a quick and dirty fix to django/core/files/images.py. I added the following right above where it says return p.image.size (​source):

try:
    exif = p.image._getexif()
except (AttributeError, ValueError):
    pass
else:
    if exif is not None and exif.get(274, 0) > 4:
        return (p.image.size[1], p.image.size[0])

[David Sanders]

Adam I'd encourage you to start a discussion on the django-developers mailing list [1] seeing as this is a behaviour change. Your suggestion seems like it could be a helpful addition but many folks have probably already encoded exif rotation into their codebases and might get an unwelcome surprise if Django started doing it… there may be a bunch of other reasons that folks would rather it not behave this way? 🤔

That being said the triage team might simply accept it :)

[1] ​https://groups.google.com/g/django-developers

[Mariusz Felisiak]

I agree with David that some discussion is needed because this change is backward incompatible. You can also subclass ImageField if the current behavior doesn't suit you.

Please ​follow the triaging guidelines with regards to wontfix tickets and take this to DevelopersMailingList to reach a wider audience and see what other think.

[Johannes Maron]

I am taking the liberty to reopen this, since I believe there is a backwards-compatible way. Thus, invalidating the previous reason to close the issue.

Both the get_image_dimensions function and ImageField can default to the current behavior while providing an explicit argument to include the EXIF rotation.

This would be a fairly minor patch. In future Django versions, we could consider deprecating the default behavior and forcing users to make an educated decision.

At the very least, this deserves a little note in the docs.

[Tim Graham]

Please ​follow the triaging guidelines with regards to wontfix tickets and take this to DevelopersMailingList to reach a wider audience and see what other think of your proposal.