I use the following command in a script:
exiftran -a -i mypic.jpg
For some pictures, I get a wrong vertical offset, which is seen as a vertical line along the right border of rotated pictures. This happens with pictures taken with my phone (Galaxy Note 3).
If I open the un-rotated picture in gthumb, and ask to "rotate physically", I get this warning:
This transformation may introduce small image distortions along one or more edges, because the image dimensions are not multiples of 8.
I have also tried
mogrify -auto-orient, which seems to work better.
Can someone explain why there is a vertical line on the right of some pictures rotated with exiftran?