Batch lossless rotate JPEG in OSX

Question

I want to losslessly rotate all JPEGs that have been shot in portrait mode and remove the rotate flag, so iPhoto doesn't stops rotating them. Any easy way to do that?

Answer 1

Found it:

jhead -autorot <filename> does it. To rotate all the files in a directory, just do jhead -autorot *.

You must have both jhead and jpegtran installed. jhead can be found here (OSX binary available). jpegtran can be found here (download the source and compile it using ./configure && sudo make all install).

Answer 2

You can also use exiftran installed though homebrew, which by default will rotate the image and then remove the exif rotation data (set it to 1).

brew install exiftran
exiftran -ai *.jpg