Toolkit XMP Metadata Support
Metadata is information that describes and helps to categorize a document. Adding good metadata is crucial for efficient document search and distribution.
Metadata is information that describes and helps to categorize a document or another object, such as a photograph or a video. It is attached to the object it is defining.
PDF metadata is used to describe the contents and subject of a document, capturing such information as Author, Subject, and Keywords. PDF metadata also includes automatically-recorded technical information such as what application was used to create the document, or its file size.
Adding good metadata is crucial for Internet documents that will be searched for among billions of other documents. Good metadata also increases the efficiency of search engines in the work space when searching for specific and unknown documents. Metadata can also be used to automate document workflows and distribute published documents through the correct channels.
For more information about PDFs and XMP metadata, see Metadata XMP: Delivering Content in Context in the ActivePDF blog.
About XMP Manager and XMP Metadata
XMP (Extensible Metadata Platform) is an XML standard for storing metadata in digital assets, such as PDFs, photos, and videos. XMP supports custom-designed sets of metadata as well as widely-used standards such as the Dublin Core properties. When a PDF is opened in a text editor the XMP metadata—stored as XML text—is human-readable, and can be easily read by scripting languages.
Metadata property sets that are based on XMP include:
- A schema that describes the properties that are used.
The schema is identified by its namespace, which includes a prefix and a unique URI (Uniform Resource Indicator). The namespace differentiates the schema from all others, even schemas that use the same name.
where myco is the prefix, and the web address serves as the URI.
- Property name and value pairs.
The property name includes the name for the namespace. For example, the name/value pair for a custom property "doc_status" that has the value "released: might be:
- myco identifies the property as belonging to a custom set of metadata.
- doc_status is the name of the myco property
- released is the value of the myco property
To display XMP metadata in a PDF editor: Press Ctrl D on your keyboard and select the Description tab > Additional Metadata button > Advanced (in the left field). See Image 1.
- Document Description and Custom Properties XMP metadata also display in the Description tab and Custom tab of the Document Properties dialog box when opened with a PDF reader.
See the next topic below: PDF Metadata Systems Managed by XMP Manager.
- For more information about PDFs and XMP metadata, see Metadata XMP: Delivering Content in Contextin the ActivePDF blog.
Image 1: XMP Advanced: displaying the Dublin Core namespace
PDF Metadata Systems Managed by XMP Manager
The metadata systems managed by XMP Manager can be grouped into these types:
- Document description
Simple name/value pairs of information that describe the document. When opened with a PDF reader, the name/value pairs can be viewed in the Description tab of the Document Properties dialog box. When opened with a PDF editor, the name/value pairs can also be viewed in the Additional Metadata dialog box.
For more details, see the XMP Document Description Properties topic in the Toolkit API Manual.
- Custom properties
Simple name/value pairs for storing custom information related to the document. When opened with a PDF reader, the name/value pairs can be viewed in the Custom tab of the Document Properties dialog box. When opened with a PDF editor, the name/value pairs can also be viewed in the Additional Metadata dialog box.
For more details, see the XMP Custom Properties topic in the Toolkit API Manual.
- XMP User properties
Metadata organized in user-defined property name/value pairs that can be extended to handle all types of information. When opened with a PDF editor, the metadata can also be viewed in the Additional Metadata/Advanced dialog box.
For more details, see the XMP User Properties topic in the Toolkit API Manual.
- Form-field information entered into XMP
Using Toolkit, you can add page-related information about form fields to the metadata.
For more details, see the XMP Form-Field Metadata topic in the Toolkit API Manual.
Note: Document Description metadata and Custom Properties metadata can also be created using the SetInfo and CustomDocInfo methods in the Toolkit object. For more details, see the the Toolkit Object Metadata topics in the Toolkit API Manual.
Technical metadata that is not edited
A PDF contains some metadata that is added during when the PDF was created or modified, and is not directly editable.
This includes such Document Description information as:
- PDF Producer
- PDF Version
- File Size
And XMP information such as: