How can I modify the EXIF orientation tag of an image?

Solution 1:

You can retrieve the existing orientation information via exiftool as follows:

exiftool -Orientation -n image.jpg

This will display the internal value of the orientation information held in the MIE tags. You can return the value as an English string by omitting the -n flag. You can find additional information here regarding particular rotation/orientation values.

Changing the orientation data with exiftool can be done as follows:

exiftool -Orientation=1 -n image.jpg

Here, the orientation is set to 1, indicating no rotation. These numbers are defined as per the EXIF specification; you can see what effect different rotation values have in the link above.

(note: you must use the -n argument when setting orientation to indicate that the value is numeric. If you forget, exiftool will interpret the orientation=x number as a string and set the wrong rotation ie. exiftool -orientation=1 image.jpg will actually set the orientation to 3 which is 'Rotate 180')

Solution 2:

My solution was the same as @Breakthrough, but I had to put the -n before -Orientation, such as

exiftool -n -Orientation=1 image.jpg