PDFlib TET PDF IFilter 4.0 Manual

3 Metadata Properties
3.1 Sources of Metadata in PDF
Most PDF documents contain document information entries, such as the Author and
Title fields. In addition to document information entries PDF documents may contain
XMP metadata. TET PDF IFilter supports indexing of several kinds of metadata in PDF
documents.
Predefined and custom document info entries. Document information entries are
considered the old and simple kind of PDF metadata. They can be displayed in Acrobat
via File, Properties... . The following document info entries are predefined in PDF:
Title Author Subject Keywords Creator Producer CreationDate ModDate Trapped
In addition to predefined document info entries custom entries can be added to the set
of document info entries. They can be displayed and edited in Acrobat (but not Adobe
Reader) via File, Properties..., Custom.
Both predefined and custom document info entries can be addressed with pCOS
paths in TET PDF IFilter (see below).
XMP properties at the document and image level. XMP (Extensible Metadata Platform 1 )
is a framework for specifying metadata. XMP is required, for example, for PDF/A conformance,
and is supported by an increasing number of applications. XMP metadata is
organized in schemas which contain a number of properties. Properties are addressed
using a namespace prefix and the property name.
XMP metadata is usually associated with the whole document. However, in PDF it is
also possible to associate XMP with individual pages, images, or other objects. In practise
this feature is mainly used for raster images. For example, a digital image may carry
the name of the photographer, copyright notes, scene details and other information. An
important source of image-related XMP metadata is Adobe Photoshop. If you create PDF
from Photoshop or use Photoshop-created images in Adobe workflows, the XMP metadata
will usually be included in the PDF document, and can be indexed with TET PDF
IFilter.
The XMP specification includes a description of all predefined XMP schemas and
properties. More information on XMP can be found at
www.adobe.com/devnet/xmp
XMP properties on the document or image level (as well as XMP associated with other
objects) can be addressed in two steps: a pCOS path identifies the relevant PDF object,
and a two-part XMP property name addresses the target XMP schema and property.
XMP metadata can be displayed and edited in Acrobat and other products of the Adobe
Creative Suite with Custom XMP panels. These are descriptions of a custom user interface
for specific XMP metadata. Sample XMP panels are installed with TET PDF IFilter;
more information and installation instructions can be found at
www.pdflib.com/knowledge-base/xmp-metadata/xmp-panels/
1. See www.adobe.com/products/xmp
3.1 Sources of Metadata in PDF 37