XMP and IPTC mapping

Question

Is there a document that identifies which fields in Photoshop and Illustrator "file info" map to the corresponding IPTC field and XMP field repectivly. Also, if I enter a value in a field that is represented in both standards will both fields be populated in the image file?
Regards
Chris

Answer 1

The 'File Info' in Photoshop since version 3.0 is stored in numerous places in a given file for various formats.
On the Macintosh, some information is stored in the resource fork for any file format:
The keywords are stored in a 'KeyW' resource and the caption is stored in a 'TEXT' resource. These resources are referenced by the 'pnot' resource. This information is readable by Aldus Fetch (now Extensis Portfolio). For more information on the format of these resources see:
Inside Machintosh: QuickTime Components
Aldus Fetch Awareness Developer's Toolkit
All of the data from File Info is stored in an 'ANPA 1000' resource. The data in this resource is stored as an IPTC-IIM version 2, record 2. For more information on the format of this resource see:
"Information Interchange Model (IIM) version 4"
Available online at:
Telephone: [phone]
Facsimile: [phone]
E-mail: David Allen, Managing Director
Post: IPTC
Royal Albert House
Sheet Street
Windsor
Berkshire
SL4 1BE
UK
On all platforms, the IIM is also stored in the data fork of the file. For file formats that can support Photoshop's image resources the data is stored as an image resource '1028' (kCaptionID) in IPTC-IIM record 2 format.
For TIFF files the caption data is stored in an image description tag '270' and all the information is stored as an IPTC-NAA record 2 in tag '33723' the tag number was chosen by inspecting files written by Iron Mike software, and is supposed to be defined in a Rich TIFF specification that I haven't been able to track down. The tag is also specified in:
NSK TIFF
The Japan Newspaper Publishers & Editors Association
Nippon Press Center Building
2-2-1 Uchlsaiwai-cho
Chiyoda-ku, Tokyo 100
For more information about the TIFF format see:
"TIFF Revision 6.0"
Available online at:
In reading the files, the following order is used with information read
lower on the list replacing information read higher:
* kCaptionID image resource
* For old Photoshop files, the caption data is read from the image resource '1008' (kOldCaptionID) or '1020' (kPrintCaptionID) (it cannot appear in both). Old PrintCaption data could coinside with caption data in some beta releases in this case the print caption data is ignored.
[NOTE version 3.0 and 3.0.1: Print caption was appended to the caption
information but this caused duplicate captions in TIFF files. This bug was fixed for version 3.0.2]
* Image Description Tag (TIFF only)
* IPTC-NAA Tag (TIFF only)
[NOTE version 3.0 and 3.0.1: TIFF data did not override the previous image resources. This bug was fixed for version 3.0.2.]
* 'pnot' resource related data (keywords and caption) (Mac only)
* 'ANPA' resource (Mac only)
[Additions for Photoshop 7.0]
* XMP Data - The kCaptionID image resource is written out with a digest
signature. The digest is re-generated from the above information when
a file is opened. If the digest doesn't match then the XMP information
for properties that that are contained by the kCaptionID resource
(IIM records, photoshop:WebStatement, and photoshop:Marked) are
dropped from the XMP Data. Otherwise, the XMP Data takes precedence over all previous data.
NOTE: The TIFF information comes prior to the image resource information on this list. This means that an edit to the TIFF info will not be recognized unless the image resource information is removed.
Photoshop Schema
The namespace prefix is ÒphotoshopÓ. The namespace is http://ns.adobe.com/photoshop/1.0/.
Property Type IIM Record Alias Category
photoshop:Caption Text 2:120 Caption/Abstract dc:description/*[@xml:lang='x-default'] External
photoshop:Author ProperName 2:80 By-line dc:creator/*[1] External
photoshop:Title Text 2:05 Object Name dc:title/*[@xml:lang='x-default'] External
photoshop:Keywords bag Text 2:25 Keywords dc:subject External
photoshop:WebStatement URL xapRights:WebStatement External
photoshop:Copyright Text 2:116 Copyright Notice dc:rights/*[@xml:lang='x-default'] External
photoshop:CaptionWriter ProperName 2:122 Writer/Editor External
photoshop:Headline Text 2:105 Headline External
photoshop:Instructions Text 2:40 Special Instructions External
photoshop:AuthorsPosition Text 2:85 By-line Title External
photoshop:Credit Text 2:110 Credit External
photoshop:Source Text 2:115 Source External
photoshop:DateCreated Date 2:55 Date Created (1) External
photoshop:City Text 2:90 City External
photoshop:State Text 2:95 Province/State External
photoshop:Country Text 2:101 Country/Primary Location Name External
photoshop:TransmissionReference Text 2:103 Original Transmission Reference External
photoshop:Category Text 2:15 Category (2) External
photoshop:Marked Boolean xapRights:Marked External
photoshop:SupplementalCategories bag Text 2:20 Supplemental Category External
photoshop:Urgency Integer 2:10 Urgency (3) External
photoshop:JobName (4) Text xapBJ:JobRef/*[1] External
xapMM:ManageTo (5) URL Relational
xapMM:Manager (5, 6) AgentName Relational
xapMM:DocumentID (7) URI Internal
(1) Explicitly not aliased to the internal creation date which denotes the document creation. This field is intended to follow the IIM conventions:
Designates the date the intellectual content of the document was created rather than the date of the creation of the physical representation. Thus a photo taken during the American Civil War would carry a creation date during that epoch (1861-1865) rather than the date the photo was digitized for archiving.
(2) This field is limited to three 7 bit ASCII characters only.
(3) Valid range is 1-8.
(4) Not aliased in Photoshop 7.0 due to bug in XMP.
(5) If xapMM:Manager is not "AdobeARM" and the ARM is not managing this
document then these properties are preserved.
(6) Set to "AdobeARM" for managed files.
(7) DocumentID will be set if it was previously blank and once set it is especially "sticky" and won't be lost even if other metadata takes
precedent and can not be set by loading XMP data from File Info although plug-ins are able to set, but not clear, this property.