All metadata standards can potentially accommodate all metadata but there are real differences in how it is produced and to what degree it becomes accessible. Anything can be put into metadata fields but at what production cost and at what effort to access it?
For pictures there is the Exif standard, which contains large amounts of information and is a widely used. An issue with Exif data however is that it is often stripped away when moving between software programs.
| Visual-Meta | ||
| Citation Metadata how to cite the document | Core Property, (Automatic) | Core Property, (Manual) in XMP or document |
| Descriptive keywords etc. to find the document | Core Property, (Manual) | Core Property, (Manual) in XMP |
| Usage Rights copyright etc. | Manual | Core Property, (Manual) in XMP |
| Structural headings etc. | Core Property, (Automatic) | Sometimes Automatic (from MS Word) |
| Connective citation references | Core Property, (Automatic) | Additional Property |
| Contextual glossary, Endnotes | Core Property, (Automatic) | Additional Property |
| Media images, tables, charts, etc. | Automatic (not currently implemented) | Additional Property |
| Errata non destructive corrections | Experimental | As ‘track changes’ |
| Computational interactive text based on criteria | Experimental | Additional Property |
| XR position & aspect in 3D space | Experimental | Additional Property |
| User Annotations | Experimental | Core Property |
Notes on Degrees of Support (automatic, manual etc.)
In the table above, where Visual-Meta is Automatic, it means that it can be automatically taken from the manuscript document and appended as metadata on export, as is usually done with Visual-Meta systems currently.
Core Property means that there are fields in the core Visual-Meta or XMP schema for this data.
Additional Property means that this data does not have a default, standard field in the workflow but can be added and is therefore not available to view in standard PDF viewer software, nor straight forward to implement in software by developers.
Notes on Categories
Descriptive metadata is used to describe documents for cataloging and finding purposes and therefore needs to be done manually in all cases, as does Usage Rights though this can be done through boilerplates.
Structural metadata, specifically headings, is in the manuscript document but very few authoring software systems exports this as PDF metadata.
(Microsoft Word can accommodate turning headings into metadata, not Apple Pages)
Visual-Meta includes Connective metadata through including the full Reference section of the document, in a machine readable format, allowing for accurate citations maps to be viewed, instantly.
Similarly, Visual-Meta supports Contextual metadata in the form of Glossaries, which can be automatically generated based on the user’s own definitions.
Media metadata can also automatically be included, if the manuscript document ‘knows’ what the media is. For example, the table above where Visual-Meta and PDF with XMP metadata is compared, could be in Visual-Meta with the rows and columns defined for instant extraction of the values for interaction when reading a single document or a corpus of thousands.
Computational text in the document refers to Vint Cerf’s notion of text which can change based on user interaction or external circumstances, such as location or time.
Further metadata, such as Errata and XR, is experimental. In Visual-Meta it is, like all the metadata, described openly for easy parsing. These can be appended as separate appendices, leaving the original Visual-Meta in place and every time there is a change in the Errata, or the placement of objects from the document in XR space, these separate–temporary–appendices get updated.
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