JPEG images: EXIF orientation

gistfile1.sh

# 1/ Read EXIF orientation flag
identify -format "%[EXIF:orientation]" myimage.jpg

# NOTE: jhead can be used too
# see http://www.sentex.net/~mwandel/jhead/
jhead -exifmap myimage.jpg | grep Ori

# 2/ Remove EXIF orientation
#    i.e. rotate the image accordingly and reset the orientation
#    flag to 1 (default, i.e. origin = TopLeft)
#    WARNING: the image file is overwritten!
#    NOTE: it also works with a wildcard: jhead -autorot *.jpg
jhead -autorot myimage.jpg

# NOTE: to simply reset the orientation flag w/o applying any
#       rotation, use the -norot option instead
jhead -norot myimage.jpg