Image metadata can provide information about place and time and thus endanger anonymity beyond the image content.
Images contain metadata in various formats:
- EXIF (Exchangeable Image Films Format)
- XMP (Extensible Metadata Platform).
- IPTC (International Press Telecommunication Council).
Metadata can contain the following information:
- Times (e.g. date and time of creation, editing, access ...)
- Geographic data (e.g. GPS location, line of sight, ...)
- Information about the camera (e.g. manufacturer, model)
- Camera settings (e.g. aperture, exposure time, flash, ...)
- Image data (e.g. height, width, resolution, compression, ...)
Potential use and misuse: The desired use of this information is offset by the undesired use. These include the following scenarios:
- Series of images can be displayed in the course of time, even if the images as copies have a different creation reason.
- If a location can be identified from the picture (e.g. with a name tag, logo, etc.), time stamps can be compared with, for example, duty rosters or other external lists. The anonymity of people may be at risk.
- Georgographic information:
- Images can be displayed on a map based on location and (possibly also) time and thus better interpreted in the individual statement - but also in the overall statement (e.g. to develop best practice)
- If the geographical position can be compared with ownership (e.g. apartment, company facility), the anonymity of people can be jeopardized.
- Geotagging images together with social media can lead to environmental damage.