Images from ipad not rotating properly
The -auto-orient operator is part of the ImageMagick image processing toolkit, to select the correct orientation of an image based on its EXIF data. Have a look at How to detect shot angle of photo ... for a more complete explanation.

The ImageMagick module integrates this function in Drupal, but they are still having an issue with autorotation. A recent patch is available there.

Your best bet is to try it out and see if it corrects your problem.