META Resources

Metadata History: Timeline

A more technical and detailed history of metadata

The International Press Telecommunications Council (IPTC) was established in 1965 to safeguard the telecommunications interests of the world press.  Since the 1970s, the organization has focused on developing and publishing industry standards for the interchange of news data. Since 1979, photographer know IPTC for creating the set of metadata attributes applied to images. The organization has remained a key player in the development of metadata.

For many years, newspapers and other news outlets received photos via an early facsimile machine. The photo, including caption and other information, were placed on a revolving drum and transmitted over telephone lines.

In 1988 Leaf, Inc. released the Leaf Desk, designed by Bob Caspe. The Leaf Desk was one of the earliest units designed for transmission of images from the field.  It consisted of a scanning stage that accommodated a three image strip of 35 mm film, a keyboard for writing captions, a modem and a small computer screen.  Since the Leaf Desk had no digital memory device, the whole scanning, captioning and transmission process was repeated each time the same image was sent to another destination.

Some of the earliest discussions about metadata as we know it today occurred just prior to the introduction of the Leaf Desk.
During a National Press Photographers Association digital show in San Francisco, photo editor Stephen Hart of the Associated Press, Senior AP Photo Editor Grant Lamos and AP Photo Editor Pete Leabo discussed the problems of sending images and cutline information in a Chinatown bar.  They realized that whatever protocol they adopted would have to dovetail with current procedures.  A year or two later at Hurley's bar in Manhattan Hart met with AP Photo Library Director Chuck Zoeller and David Rocha, also of AP, to discuss the coming of the Leaf Desk.  Though there were some guidelines from the American Newspaper Publishers Association (now known as the Newspaper Association of America), these may have been two of the earliest discussions of photo metadata fields.

Not long after introduction of the Leaf Desk came the Spooler, an external hard drive that let photographers scan and save images before transmission. As such, photographers could scan several images, then send them as a group.

Manually writing metadata into each and every image file can be a tedious job, which was why  Mike Evans, formerly President Ronald Reagan's photographer, started Iron Mike Software to facilitate embedding metadate into Adobe's Photoshop 95.  Though the Iron Mike approach was useful, there were incompatibilities because Adobe and Iron Mike wrote the data differently. Leaf Desk would pick up metadata from either Adobe or Iron Mike software.  But, if one wrote the data using Iron Mike and then did something in Photoshop, the Adobe program would not recognize the Iron Mike annotations and, in turn, Leaf Desk would find no information in the metadata file.  Still, AP shooters  liked Iron Mike software because it could write simultaneously to a batch of images, which Photoshop could not. Apple Computer also got involved in the early days of metadata when it introduced a low-end digital camera bundled with imaging software that accepted Photoshop plug-ins, including Iron Mike.  About this time, AP created Photo Lynx, a photo browser for Apple's Macintosh computers with a docking station that offered Leaf transmission functions.

IPTC developed the Information Interchange Model (IIM) in 1990.  IMM provides specifications for metadata fields. Though it  was never intended specifically for use with photos, Adobe adopted the standard in 1995 when it chose 20 photo metadata fields from the IIM to be included in Photoshop. The IMM schema was updated in 1999. In 1997 Adobe Systems, Inc., standardized on the use of the Image Resource Block (IRB) method of storing metadata, which adds different kinds of image data –– including, but not limited to metadata –– to a digital picture.

Photo metadata took a conceptual leap forward in 1994 when Adobe outlined the specifications for embedding the information into a digital Image Resource Block (IRB), often  called IPTC headers.  Adobe chose 20 fields for use in Photoshop 95. Though this was a bit limited by today's standards, the ability to embed information into JPEG and TIFF images was the basis of the image management system that exists today.

In 2001 Adobe introduced the Extensible Metadata Platform (XMP)
, a successor to the Image Resource Blocks. XMP represents the same types of metadata as IPTC, but uses Extensible Markup Language (XML), which is coded instructions about displaying text, and  Resource Description Framework (RDF), a simplified general-purpose digital language for representing information. Says Adobe: "With an XMP-enabled application, information about a project can be captured during the content-creation process and embedded within the file and into a content-management system. Meaningful descriptions and titles, searchable keywords, and up-to-date author and copyright information can be captured in a format that is easily understood by you as well as by software applications, hardware devices, and even file formats."

In 2005 Adobe released its Creative Suite 2, which included the new IPTC Core. IPTC core was the result of an IPTC/Adobe collaboration.  It includes and defines most IIM fields previously adopted by Adobe. New fields were added including new subject, scene and intellectual genre codes.  Two additions to the geographic information let photographers record places smaller than a city and areas outside municipalities as well as codes for countries. The IPTC Core panels were backwards compatible and could be used in the CS version of Photoshop as well, however, this did require that the user manually install the panels.

A revision to the IPTC Core was released in 2008 along with a new IPTC Extension schema. The IPTC Extension 1.0 Schema complements and extends the set of IPTC Core metadata properties, to include additional fields that are shared with the PLUS schema, such as model and property release info, as well as more detailed location information and much more.

Currently, all digital cameras embed Exchangeable Image File Format (Exif) technical metadata
about the creation of an image. Exif data includes information such as the camera's make, model and serial number; the date and time the image was made; shutter speed; ISO; and the lens used. Established in 1985 by the  Japanese Camera Industry Association, the predecessor to the Camera & Imaging Products Association, Exif is also used by some image scanners. RAW camera processing software can use Exif information to accurately render images. New technologies such as Exif Print incorporate photographic information into printing processes for improved results. Today, the Japan Electronics and Information Technology Industries Association manages the Exif standard.

Timeline of IPTC and related Metadata Standards

1979: IPTC defines a set of metadata attributes.
1991: IPTC revises attributes, releases new version dubbed the “Information Interchange Model” or IIM.
1994-95: Adobe Photoshop adopts Image Resource Block (IRB) / IPTC Headers.
2001: Adobe launches the Extensible Metadata Platform or XMP.
2005: IPTC/Adobe collaboration releases IPTC Core in Creative Suite 2.
2007: IPTC and IFRA hold first International Photo Metadata Conference and release white paper.
2008: IPTC releases revised IPTC Core and new IPTC Extension schemas.

History of the Exif (Exchangeable Image File Format) Standard

October 1995: Version 1 established as a JEIDA standard. Defined the structure, consisting of an image data format and attribute information (tags), and basic tags.
November 1997: Version 1.1 kept the essential provisions of Version 1.0 and added provisions for optional attribute information and format operation.
June 1998: Version 2 added sRGB color space, compressed thumbnails and audio files.
December 1998: Version 2.1 Upgraded and expanded the storage format and attribute information. Added recommended compatibility details as a supplement to Version 2.0
February 2002: Version 2.2 added information to Version 2.1 to improve print finishing
September 2003: Version 2.21 added optional color space (Adobe RGB)
Source: Hiroshi Maeno, Canon Inc. June, 7, 2007, First International Photo Metadata Conference, Florence, Italy.