Lossless Rotation with jhead and jpegtrans
I like my pictures rotated in such a way that I don’t have to depend on application support for them to be displayed correctly.
jpegtran (pre-installed on most distros) is a wonderful application with many features, including lossless rotation, but it’s too laborious for my purposes. That’s where
jhead comes in.
You can simply go into a directory, run a command like the following, and everything will be done automatically for you.
jhead -autorot *.JPG
Of course I wouldn’t run it if you don’t have a backup available. I always keep the pictures around on my camera until I’ve confirmed that all processing was successful and then I still don’t delete them until the adjusted files were also copied to my external HDD in my semi-regular backup regime.
Another utility that can perform the same task is
exiftran, but despite being more or less dedicated to this very purpose it’s not even easier to use: I’d expect
exiftran *.JPG to default to the equivalent of the
jhead -autorot *.JPG command I posted above, but instead you have to use
exiftran -ai *.JPG. All other things being equal for my purposes, I decided to go with jhead because it has many more features — although last year I decided that exiv2 is superior to jhead in ease of use for most of those features.
If you’re just looking for the occasional lossless rotation, you could also try the Geeqie image viewer and manager. It integrates calls to exiftran, but beware that you explicitly have to choose the lossless option, as there are also lossy rotate options.
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