On 12 December 2011 18:18, Erik Moeller <erik(a)wikimedia.org> wrote:
On Mon, Dec 12, 2011 at 7:55 AM, David Gerard
<dgerard(a)gmail.com> wrote:
* How many existing uploads, used on the wikis,
were previously
wrongly rotated and were fixed by the feature?
* How many existing uploads, used on the wikis, were previously
correctly rotated and were messed up by the feature?
As far as I understand the issue, and others can jump and correct me
if I'm getting it wrong:
Technically, nothing was "messed up" by the feature. Rather, the
software previously did not take EXIF rotation into account, and some
images had incorrect EXIF rotation information to begin with. Those
images are now shown in an incorrect rotation to the user, because the
incorrect EXIF rotation info is being evaluated.
That's a big technicality. Surely the most important thing is how the
images display to users? There were right before and now they aren't.
That may not be technically messed up, but it is messed up in reality.
It's important to understand this, because it
means that those images
have been causing problems for re-users all along. If you open those
images with modern image editing/viewing software, they will either be
automatically rotated, or you'll be prompted by the software whether
to apply the rotation noted in the EXIF tag.
Indeed, it's good to get these images fixed, but surely it would have
been better to fix them rather than just break the workaround that was
stopping people noticing they were broken?
The situation has been significantly exacerbated by a
recent need to
purge old thumbnails to free up diskspace.
How big a contributing factor has that been? As I understand it, only
thumbnails of unused images were purged. People (including me) have
been stumbling over incorrect images in articles - have they just been
unlucky and the thumbnail happened to expire at the wrong time?
So, while the cleanup that's happening now is very
frustrating (and I
definitely agree we could have anticipated and communicated this
better), it's a cleanup that's long overdue. (Either by stripping EXIF
info from files altogether, or by ensuring that the rotation of the
image matches the one in the metadata.)
Is there more that we can do at the present time to help?
I think, at the moment, the most useful thing would be to automate
finding the broken images (basically, it's all images uploaded before
the feature was introduced that have a non-zero EXIF rotation).