Embedded Metadata
UPDATED: March 2023
Metadata is a core component of digital objects. Some embedded metadata stores technical information that is necessary for applications, e.g. Adobe Photoshop, to open, edit, and save file(s). However, descriptive and rights information can also be embedded in some file types. OSUL follows the FADGI recommendations developed by the Smithsonian for embedding descriptive and rights information (http://www.digitizationguidelines.gov/guidelines/GuidelinesEmbeddedMetadata.pdf). (Note: If FADGI link to embedded guidelines does not work, the documentation can also be found on the Smithsonian website at https://repository.si.edu/handle/10088/9719.) TIFF tags can be referenced via LOC's Sustainability of Digital Formats website (https://www.loc.gov/preservation/digital/formats/content/tiff_tags.shtml). More details about embedded metadata tags can be found in the ExifTool website (https://exiftool.org/TagNames/index.html) and Exiv2 website (https://www.exiv2.org/metadata.html). There are fewer embedded metadata fields for PDFs; exiftool provides a list (https://exiftool.org/TagNames/PDF.html).
At OSUL, embedded metadata is viewed and edited with ExifTool (https://www.sno.phy.queensu.ca/~phil/exiftool/), Adobe Bridge, and Adobe Photoshop.
Embedded Metadata for Still Images
In collaboration with Preservation & Digitization and the Digital Preservation Librarian, Metadata Initiatives ensures that essential embedded metadata is recorded in digital still images for ingest to DC. This site has a useful analogy regarding the types of metadata embedded in image files (https://www.photometadata.org/META-101-metadata-types).
Resources:
- Embedded Metadata Template (download)
- Embedded Image and PDF Metadata, Digital Rice Projects
- Car Library Project: ExifTool - Reading and Writing Embedded Metadata
Adobe products
Depending on whether you use Adobe Bridge or Photoshop, the embedded metadata will be visible in different sections. The table below explains the differences.
In Adobe Bridge, use the Metadata panel to view metadata for a specific file or a group of files. In Adobe Photoshop, open the specific file and go to File > File Info to view and edit embedded metadata in digital images.
Note: Sometimes Adobe products embeds the same metadata in multiple fields - see mapping to ExifTool. That duplication is not necessary.
Errors & Corrections - March 2023: The embedded metadata template has an error. It erroneously maps Source values to the tag by-line. The by-line tag has consequently been removed from the table below.
Adobe Bridge Section & Field Name | Adobe Photoshop Section & Field Name | ExifTool Tag | XMP Tags | Example | Entry | Embeds in PDF? | Explanation / Notes | ||
---|---|---|---|---|---|---|---|---|---|
File Properties | Filename | n/a | n/a | FileName | d_19745.tif | auto-populate | |||
Document Type | Basic | Format | Format | <dc:format> | TIFF Image (in Bridge) image/tiff (in Photoshop and ExifTool) | auto-populate | |||
Date Created | Basic | Creation Date | DateTimeCreated ------------ dateTimeOriginal | <xmp:CreateDate> --------- <exif:DateTimeOriginal> | 5/13/2019, 2:09:33 PM | auto-populate | |||
File Size | n/a | n/a | FileSize | 134.31 MB | auto-populate | ||||
Dimensions | Camera Data | Image Size | ImageSize ExifImageWidth/ExifImageHeight and ImageHeight/ImageWidth (for separate values) | 11334 x 4141 | auto-populate | Dimensions of digital image. | |||
Dimensions (in inches) | n/a | n/a | 18.9" x 6.9" | auto-populate | This is useful to compare the size of the digital object as it represents the original object. Ideally, this measurement should accurately reflect original object. If it does not, consult Preservation & Digitization for guidance. | ||||
Resolution | Camera Data | Resolution | 600 ppi | auto-populate | |||||
Bit Depth | n/a | n/a - Go to Image > Mode. | BitsPerSample | <tiff:BitsPerSample><rdf:Seq><rdf:li> | 8 | auto-populate | Values displayed differently between platforms. | ||
Color Mode | n/a | n/a - Go to Image > Mode. | ColorSpaceData | RGB | auto-populate | As per Preservation & Digitization, still images intended for DC should be digitized to RGB. | |||
Color Profile | n/a | n/a - Go to Edit > Assign Profile. | ProfileDescription | Adobe RGB (1998) | ? | As per Preservation & Digitization, digitized still images should conform to Adobe RGB (1998) color profile. | |||
ICCProfileName | <photoshop:ICCProfile> | Adobe RGB (1998) | ? | There is a documented issue with how ExifTool reads color info. For ColorSpace, sRGB is the value 1 and Adobe RGB is the value 2. However, ExifTool will display anything other than 1 as "Uncalibrated" for the ColorSpace field. Amy McCrory recommends referring to the ICCProfileName to verify that "Adobe RGB (1998)" is the value. | |||||
IPTC Core | Creator | IPTC | Creator | creator artist | <dc:creator><rdf:Seq> | BICLM, Ohio State University | manual | Yes - both exif tags | OSUL unit that created the digital object, e.g. "Preservation & Digitization, Ohio State University". Notes:
|
Date Created | Date Created | createDate dateTimeOriginal | 5/13/2019, 2:09:33 PM | auto-populate | auto-populate | The capture device, e.g. scanner, digital camera, should automatically record the date and time. Note: In Photoshop, this field also populates Origin: Date Created. | |||
Title | Basic | Document Title | objectName title | <dc:title><rdf:Alt><rdf:li xml:lang="x-default"> | d_19745 | manual | Yes - title exif tag | Identifier(s) for digital image and/or original object, e.g. call number. 64-character limit (with spaces) in this field. | |
Source | IPTC | Source | source | <photoshop:Source> | BICLM, Ohio State University | manual | Yes - source exif tag | OSUL unit that owns or manages the digital object and/or analog object. Note: Due to 32-character limit (with spaces) in this field, unit may need to be abbreviated. | |
Copyright Notice | Copyright Notice | rights copyrightNotice copyright | <dc:rights><rdf:Alt> | http://rightsstatements.org/vocab/InC/1.0/ | manual | Yes - rights and copyright exif tags | Rights statement provided by Copyright Services for DC record. 128-character limit (with spaces)in this field. | ||
Copyright Status | Basic | Copyright Status | copyrightFlag marked | Copyrighted | manual | Yes - "TRUE" for copyrighted; "FALSE" for public domain | Drop-down options: Copyrighted, Public Domain, Unknown. Choose "Unknown" if copyright status is complicated. | ||
Rights Usage Terms | IPTC | Rights Usage Terms | usageTerms | <xmpRights:UsageTerms><rdf:Alt><rdf:li xml:lang="x-default"> | This item, made available for research and educational purposes, may be protected by copyright; the user is responsible for making a final determination of copyright status. | manual | Yes | Rights note provided by Copyright Services for DC record. | |
Camera Data (Exif) | Make | Camera Data | Make | Make | <tiff:Make> | Better Light | ? | Ideally, the capture device, e.g. digital camera, scanner, should automatically populate this information. If it does not, it will need to be added. While some applications refer to this as camera make, the field has traditionally be used for the scanner manufacturer as well. | |
Model | Model | Model | <tiff:Model> | Model Super8k | ? | Ideally, the capture device, e.g. digital camera, scanner, should automatically populate this information. If it does not, it will need to be added. While some applications refer to this as camera make, the field has traditionally be used for the scanner model as well. |
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