What Is Metadata in Photography?

Understanding the hidden information in photo files

Metadata viewed in Photoshop



Metadata refers to descriptive information embedded inside an image or another type of file. Metadata is becoming increasingly important in this age of digital photos, as photographers look for ways to include image information that's portable and stays with the file.

One way metadata is created is through the extra information almost all digital cameras store with photos. This metadata is called EXIF data, which stands for Exchangeable Image File Format. Most digital photo software can display EXIF information, but you usually can't edit it.

The Most Common Metadata Formats

However, there are other types of metadata that allow you to add your own descriptive information within a digital photo or image file. This metadata might include the characteristics of the photo, copyright information, a caption, credits, keywords, creation date and location, source information, or special instructions. Two of the most commonly used metadata formats for image files are IPTC and XMP.

  • IPTC is the standard developed in the 1970s by the International Press Telecommunications Council. It was developed as a standard for exchanging information between news organizations and has evolved over time. Around 1994, Adobe Photoshop's File Info form enabled users to insert and edit IPTC metadata in digital image files, so it was adopted by stock photo agencies and other publishing businesses outside of the news media.
  • XMP is the new XML-based Extensible Metadata Platform developed by Adobe in 2001. Adobe worked with the IPTC to incorporate the old IPTC headers into the new XMP framework, and in 2005 the IPTC Core Schema for XMP specification was released. XMP is an open-source, public standard, making it easier for developers to adopt the specification in third-party software. XMP metadata can be added to many file types, but for graphic images, it's generally stored in JPEG and TIFF files.

Much of today's photo-editing and image management software offers capabilities for embedding and editing metadata in your files, and there are also many specialized utilities for working with all types of metadata including EXIF, IPTC, and XMP. Some older software doesn't support embedded metadata, and you risk losing this information if you use such a program to edit and save files.

Prior to these metadata standards, every image management system had its own proprietary methods for storing image information, which meant the information wasn't available outside of the software; if you sent a photo to someone else, the descriptive information didn't travel with it. Metadata allows the information to be transported with the file in a way that can be understood by other software, hardware, and end users. It can even be transferred between file formats.

Photo Sharing and Metadata Fears

Recently, with the rise of photo sharing on social networks like Facebook, there's been some fear and concern about personal information such as location data being embedded in the metadata of photos shared online. These fears are generally unfounded since all the major social networks strip out most metadata including location information or GPS coordinates.