Photoshop Image Resources

Revision as of 12:35, 5 September 2016

Photoshop Image Resources is a metadata format native to PSD files, but which is also sometimes used in TIFF, JPEG, and other image formats.

Format details

Photoshop Image Resources consists of a sequence of blocks, each with a numeric Resource ID indicating the type of data stored in the block. Each block also contains a name, but the name is often left empty.

Each block begins with ASCII characters "8BIM", a signature which appears in several Photoshop formats.

Not all Resource IDs are publicly documented.

Apparently Photoshop data (at least in Mac formats) also makes use of the ANPA-1312 format, a news-media industry markup format, for metadata storage.

Plug-in resources

Custom application data ("plug-in resources") can be stored using resource IDs 4000–4999 (0x0FA0–0x1387). There might be more information about this somewhere in the Photoshop SDK.

[TODO: How are these resources identified? 1000 ID numbers seems insufficient for global uniqueness. Some or all plug-in resources appear to begin with a FourCC.]

[TODO: Is there any documentation available about specific plug-in resource formats?]

Related formats

• In a TIFF file, tag 34377 contains Photoshop Image Resources.

• In a JPEG file, an APP13 marker with an identifier of "Photoshop 3.0" contains Photoshop Image Resources.

• Resource ID 0x0404 contains IPTC data.

• Resource ID 0x040c may contain a thumbnail in JPEG/JFIF format.

• Resource ID 0x040F contains an ICC profile.

• Resource ID 0x0422 contains Exif data.

• Resource ID 0x0424 contains XMP data.

See also Photoshop.

Specifications

• Adobe Photoshop File Formats Specification
  • See PSD for other versions.

References

• ExifTool Photoshop Tags