MediaWiki will use Orientation information from XMP as well (Specifically, the orientation tag in the http://ns.adobe.com/tiff/1.0/ namespace. The http://ns.adobe.com/tiff/1.0/ namespace in XMP is for encoding exif information in XMP form). If there is a conflict between the XMP tiff:Orientation and the Exif Orientation tag in ifd0, the tag in IFD0 takes priority.

I'm unsure if the current behaviour is correct or should be changed.

saibotrash wrote:

Thanks. But: Hmpf! .. that gets really complicated... That EXIF-based rotation deployment is throughout a failure. Not even the devs know what really happens - apparently. :-(

Should we adjust Rotatebot now to also take XMP into account or will this be removed in MediaWiki?

Should we adjust Rotatebot now to also take XMP into account or will this be
removed in MediaWiki?

Well in theory, if you're rotating something, you should adjust all the rotation tags for complete correctness. Adjusting the XMP will never hurt anything

As for if using XMP's tiff:Orientation should be removed from MediaWiki - Good question. I don't know what the correct thing to do here is?

saibotrash wrote:

half off topic -
(In reply to comment #3)
Bawolf: "Well in theory, if you're rotating something, you should adjust all the rotation tags for complete correctness."
(as written in IRC) There is just a minor problem: How should I know and understand any metadata format which could be used? I guess there are many more. I could strip all except jpeg data. But this would make users very unhappy.

I've disabled extracting tiff:Orientation in r99632