What's the point of having it (the "orientation" tag in the exif data) if you're then going to have to rotate things anyway?
There are advantages to using the orientation tag if you have a client that can auto-rotate on the fly, because permanently rotating the original photo results in a loss of quality due to the recompression of the image.
It's crazy advice that people should be rotating photos. If you do then if the exif information is used (which it blooming well should be) then if you've pre-rotated then the photo will become over rotated.
Not necessarily.TMS sends photos to client hardware (or software) without modification. If a photo has the orientation tag set, we pass on this data to the client and it should rotate the photo on the fly. Some clients ignore the orientation tag, in this case, your only option is to manually rotate the image.
Even with clients that can rotate photos on the fly (using the orientation tag), there are still situations where you have manually rotate the image to get it to display properly. Sometimes the orientation tag is set incorrectly by auto import software. Other times it’s set incorrectly by the camera itself. In short, we’ve found it is often not reliable. That is why we handle this situation this way.
Why, why, WHY can't DLNA recommend / see the sense in the exif rotation data being used? Everyone else uses it and it's a great innovation that virtually all cameras now will store it when taking the photo in the first place. PCs, macs will all recognise it and display photos accordingly. This approach is just lunacy.
This is a good question. DLNA could recommend that EXIF rotation be taken into account when displaying a photo but it does not.
The bottom line is, you have brought up some very good issues. As a result, I plan to modify the photo section of the 'Best Practices' to give more information on this topic.
Thanks to Christian Gran for providing input on this answer.
- Rick
