[Development] Rotating JPEG images by default

[Olivier Goffart]

On Friday 17. April 2015 11:37:52 Friedemann Kleint wrote:
> Hi,
> 
>  >>If we go with the QImageReader level, it could be an
> 
> QImageIOHandler::Option,
> 
>  >and possibly be set different between JPEG and TIFF by default. The real
>  >problem is what we decide the default for JPEG should be now.
> 
> Can we add an API making this settable until the beta?  - I think
> automatic rotation is a really cool feature for any viewer-like
> application and saves writing a lot of quite advanced code (using memory
> mapping of files and endian-dependent word fiddling on platforms that
> don't have libexif or similar).

Personally, I was really happy to see that fixed. I even backported it to 5.3 
for a customer.

The use case is that we have code like 

 QPixmap myPixmap(fileName);

So the API should span in many places QImage, QPixmap, QImageReader, 
QImageIOHandler, ...

It is true that it is a behaviour change. But now it is too late anyway, and 
reverting the patch would make another behaviour change.

The question is if there are application that need to access the original 
orientation. And I think it might make sens to have such metadata available 
form QImage or so (we have QImage::text already)
But at this point, I suppose that if we really need it, it should wait Qt 5.6

-- 
Olivier 

Woboq - Qt services and support - http://woboq.com - http://code.woboq.org