Metadata

Metadata

AKA: Headers, tags, Exif data, IPTC headers

WHATText attached to the image file
HOWUsing File Info in Photoshop
PROEasy, free, informative
CONCan be removed

Contents

  1. Introduction
  2. Formats
  3. Exif vs. IPTC
  4. Metadata in RAW files
  5. Metadata & microstock
  6. Drawbacks of metadata
  7. Metadata Viewers
    1. Operating systems
    2. Online
    3. Browser extensions
    4. Desktop applications
  8. Metadata Editors
    1. Free
    2. Paid
  9. Editing metadata in Photoshop
  10. Making a Template
  11. Resources

Introduction

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
TIFFTagged Image File FormatThis 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
XMPExtensible Metadata PlatformThis is the data language used to encode metadata, including IPTC and Exif tags.
Key Metadata Schema (groups of tags)
IPTCInternational Press Telecommunications CouncilNewspaper-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
ExifExchangeable image file formatCamera tags such as camera make and model, pixel count, date, exposure, metering, ISO, flash, copyright, GPS. Exif v2.2
JFIFJPEG File Interchange FormatImage tags that are beyond the JPEG standard, such as for color space, resolution, aspect ratio. Similar to Exif.
PLUS LDFPicture Licensing Universal System License Data FormatLicensing tags for image licensors and licensees. PLUS License Data Format
DCDublin CorePublishing 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.

Microstock

Note that microstock agencies may delete or change the metadata before licensing.

Drawbacks of Metadata

Metadata can be removed (stripped) from photos.

Metadata Viewers

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.
  • Linux
    Right-click on the photo and choose “Properties”.

Online metadata viewers

Browser extensions

Desktop applications

Metadata Editors

Freeware

Paid

Editing metadata in Photoshop

File > File Info. You can make a metadata template with all your information and merge it with your image files.

Metadata Template

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.

Metadata Resources

See also:

Next: Thwart Copying »

Comments

Comments


Reply by Buddy

May 18, 2013

How can I extract metadata data into a text file?


Reply by Ajitbalaji

November 17, 2012

ElisabethMarch 26, 2011Thanks so much for posting this. I have my ditgail scrapbooking supplies meticulously catalogued in PSE5 but I noticed that my PNG files were not tagged outside of my catalog.You just gave me the missing piece to my digi organization puzzle!I’ll try this out eventually and let you know how it goes.Thanks again!


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