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SECTION 10.2 Metadata
Example 10.1 shows a typical document information dictionary.
Example 10.1
1 0 obj
<< /Title ( PostScript Language Reference, Third Edition )
/Author ( Adobe Systems Incorporated )
/Creator ( Adobe FrameMaker 5 . 5 . 3 for Power Macintosh® )
/Producer ( Acrobat Distiller 3 . 01 for Power Macintosh )
/CreationDate ( D : 19970915110347 - 08 ' 00 ' )
/ModDate ( D : 19990209153925 - 08 ' 00 ' )
>>
endobj
10.2.2 Metadata Streams
Metadata, both for an entire document and for components within a document,
can be stored in PDF streams called metadata streams (PDF 1.4). Metadata
streams have the following advantages over the document information dictio-
nary:
• PDF-based workflows often embed metadata-bearing artwork as components
within larger documents. Metadata streams provide a standard way of pre-
serving the metadata of these components for examination downstream. PDF-
aware applications should be able to derive a list of all metadata-bearing
document components from the PDF document itself.
• PDF documents are often made available on the Web or in other environments,
where many tools routinely examine, catalog, and classify documents. These
tools should be able to understand the self-contained description of the docu-
ment even if they do not understand PDF.
Besides the usual entries common to all stream dictionaries (see Table 3.4 on
page 62), the metadata stream dictionary contains the additional entries listed in
Table 10.3.
The contents of a metadata stream is the metadata represented in Extensible
Markup Language (XML). This information is visible as plain text to tools that
are not PDF-aware only if the metadata stream is both unfiltered and unencrypt-
ed.
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