exiftran is a command line utility to transform digital image jpeg images. It can do lossless rotations like jpegtran, but unlike jpegtran it cares about the EXIF data: It can rotate images automatically by checking the exif orientation tag, it updates the exif informaton if needed (image dimension, orientation), it also rotates the exif thumbnail. It can process multiple images at once.
I'm pretty sure several people mentioned this package in comments regarding the jpegtran command (from the libjpeg-progs package), but props go to Giulio M. for submitting it.
More information on this package can be found on the Debian web site.
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