AKA: Headers, tags, Exif data, IPTC headers
|WHAT||Text attached to the image file|
|HOW||Using File Info in Photoshop|
|PRO||Easy, free, informative|
|CON||Can be removed|
- Exif vs. IPTC
- Metadata in RAW files
- Metadata & microstock
- Drawbacks of metadata
- Metadata Viewers
- Metadata Editors
- Editing metadata in Photoshop
- Making a Template
Digital image files allow you to add text fields called “metadata” that label the image. You can include your copyright notice, contact details, and a wealth of other information as metadata. Unless removed by someone, metadata will stay attached to your image even if it gets copied and pasted around the Web.
Metadata is stored as standard ASCII text in a data file which is attached as a header to the image file. Metadata “tags” can be written by the camera or be input directly by you via photo-processing software such as Photoshop.
Formats (Exif, IPTC, et al.)
There are several overlapping standards for metadata tags, particularly, in the field of photography, “Exif” and “IPTC.” You don’t need to know the difference between the various formats as they’re all treated the same — a copyright notice in an Exif tag is equal to a copyright notice in an IPTC tag (they’re both just a string of text). But since you’ll bump into these terms, here’s a primer:
|Key Metadata Formats|
|TIFF||Tagged Image File Format||This is an overall container format. A TIFF file includes the metadata and the image. Within a TIFF can be XMP-encoded metadata that use IPTC and/or Exif tags, and a JPEG image. TIFF 6.0 Spec|
|XMP||Extensible Metadata Platform||This is the data language used to encode metadata, including IPTC and Exif tags.|
|Key Metadata Schema (groups of tags)|
|IPTC||International Press Telecommunications Council||Newspaper-style tags such as the author, caption, copyright notice, date, event name, keywords, location, model name. There are two groups: IPTC Core and IPTC Extension. IPTC|
|Exif||Exchangeable image file format||Camera tags such as camera make and model, pixel count, date, exposure, metering, ISO, flash, copyright, GPS. Exif v2.2|
|JFIF||JPEG File Interchange Format||Image tags that are beyond the JPEG standard, such as for color space, resolution, aspect ratio. Similar to Exif.|
|PLUS LDF||Picture Licensing Universal System License Data Format||Licensing tags for image licensors and licensees. PLUS License Data Format|
|DC||Dublin Core||Publishing tags for a wide range of applications. DCMI|
Exif vs. IPTC
Exif is technical; IPTC is descriptive. PLUS is administrative.
Here’s a good way to remember the difference: Exif is the camera, and IPTC is the subject. Exif stores the lens size automatically; IPTC requires the photographer to type in a caption. A location stored in Exif would be in numbers (as the GPS coordinates), and in IPTC it would be in text (as the city, state and country).
Exif and IPTC are similar and overlapping schema that can both store copyright information. Exif is limited and no longer maintained, but is used as a legacy format by camera manufacturers. IPTC headers (tags) are supported by Adobe, Apple, Canon, Microsoft and Reuters.
What about “RAW” files?
Data direct from a camera’s sensor is encoded in a proprietary, manufacturer-specific format generically known as “RAW.” Virtually all RAW files (including those by Canon, Hasselblad, Leica, Mamiya, Nikon, Olympus, Panasonic, Pentax, Phase One, Sony) can include Exif tags as they are based on the TIFF format.
Originally named for Tagged Image File Format, TIFF is a flexible and widely-used image file format that includes header tags. The tags describe how the image is encoded and allow TIFF to be used as a universal container to hold other formats, including JPEG and proprietary RAW formats. Adobe owns the copyright for TIFF and XMP. IPTC and Exif metadata are stored in the TIFF 6.0 tag information format.
Note that microstock agencies may delete or change the metadata before licensing.
Drawbacks of Metadata
Metadata can be removed (stripped) from photos.
Your operating system allows you to read the Exif data of your images:
- Microsoft Windows
Right-click on the photo, select “Properties”, and switch to the “Details” tab.
- Apple OS X
Right-click on the photo, select “Get Info”, and expand the “More Info” section.
Right-click on the photo and choose “Properties”.
Online metadata viewers
- Exif Reader Windows
- Exif Tag Parsing Library
- Exif Viewer for Mac OS X
- Opanda IExif and IExifPro Windows / Firefox
- AmoK Exif Sorter for renaming photos
- Full Image Info
- GeoSetter freeware for Windows
- GIMP GNU Image Manipulation Program
- Image Info Toolkit
- IrfanViews freeware graphic viewer
- iTag photo tagging software
- Microsoft Windows Live Photo Gallery
- PhotoMe photo metadata editor
- XnView freeware to convert graphic files
- Adobe Bridge
- Adobe Photoshop
- Adobe Photoshop Elements
- Adobe Photoshop Lightroom
- Apple Aperture
- Apple iPhoto
- BreezeBrowser Pro
- Camera Bits Photo Mechanic
- JetPhoto Studio 5
- Photools.com iMatch
Editing metadata in Photoshop
File > File Info. You can make a metadata template with all your information and merge it with your image files.
You simplify the process by setting up a single metadata template which can then be applied to all your photos. Use a metadata editor to type in your copyright and contact information. Then (from Adobe Photoshop), click on the flyout menu at the top right and select “Save Metadata Template” with a suitable file name. On your next photo, you can click on the same flyout menu and your template should be listed. Check that the correct year is used.