Image Orientation¶

Using Exiftool¶

Assuming you have Docker installed and want to run exiftool with Debian 12 "Bookworm", you can simply run this command to open a terminal:

docker run --rm -v ${PWD}:/test -w /test -ti debian:bookworm bash

This will mount the current working directory as /test. Of course, you can also specify a full path instead of ${PWD}.

The available Ubuntu, Debian and PhotoPrism images can be found on Docker Hub:

Now install exiftool and any other packages you need, e.g. libheif-examples to convert HEIF images to JPEG, via apt:

apt update
apt install -y exiftool libheif-examples

To view the image metadata, run exiftool -n <filename> and optionally use grep to filter the output:

root@1ad9fb887a4f:/test# exiftool -n IMG_8437.HEIC.jpg | grep ation
File Modification Date/Time     : 2022:09:18 08:16:28+00:00
Orientation                     : 6
Exposure Compensation           : 0
root@1ad9fb887a4f:/test# exiftool -n IMG_8437.HEIC | grep ation
File Modification Date/Time     : 2022:09:17 16:57:40+00:00
Orientation                     : 6
Exposure Compensation           : 0
HEVC Configuration Version      : 1
Min Spatial Segmentation IDC    : 0
Rotation                        : 270

Rotation and Orientation are the important values you should pay attention to and compare. The rotation is in degrees.

Exiftool Parameters¶

-n displays the raw values without changes
-j will format the output as JSON
-g groups the output by metadata source

Exif Values¶

The Exif orientation values are numbered from 1 to 8:

= 0 degrees: the correct orientation, no adjustment is required.
= 0 degrees, mirrored: image has been flipped back-to-front.
= 180 degrees: image is upside down.
= 180 degrees, mirrored: image has been flipped back-to-front and is upside down.
= 90 degrees: image has been flipped back-to-front and is on its side.
= 90 degrees, mirrored: image is on its side.
= 270 degrees: image has been flipped back-to-front and is on its far side.
= 270 degrees, mirrored: image is on its far side.