關於 PDFlib TET PDF IFilter

從 PDF 文件中提取文本和元資料。

PDFlib TET PDF IFilter extracts text and metadata from PDF documents and makes it available to search and retrieval software on Windows. This allows PDF documents to be searched on the local desktop, a corporate server, or the Web.

TET PDF IFilter extracts text and metadata from PDF documents and makes it available to search and retrieval software on Windows. This allows PDF documents to be searched on the local desktop, a corporate server, or the Web. TET PDF IFilter is based on the patented PDFlib Text Extraction Toolkit (TET), which is a developer product for reliably extracting text from PDF documents.

TET PDF IFilter is a robust implementation of Microsoft’s IFilter indexing interface. It works with all search and retrieval products which support the IFilter interface, e.g. SharePoint and SQL Server. Such products use format-specific filter programs – called IFilters – for particular file formats, e.g. HTML. TET PDF IFilter is such a program, aimed at PDF documents. The user interface for searching the documents may be the Windows Explorer, a Web or database frontend, a query script, or a custom application. As an alternative to interactive searches, queries can also be submitted programmatically without any user interface.

Based on patented TET technology
PDFlib TET, the basis of TET PDF IFilter, was first released in 2002, and has been used by customers worldwide in server and desktop environments. As an alternative to extracting PDF page contents and metadata as raw text, TET can supply the document contents in XML format. TET is also available as a free plugin for Adobe Acrobat; this plugin allows interactive test and evaluation of TET’s superior text extraction.

Unique advantages
TET PDF IFilter offers the following advantages:

  • Indexes not only page content, but also metadata, bookmarks, PDF attachments, and PDF packages/portfolios
  • Extracts text even from PDFs where Acrobat fails
  • Indexes XMP image metadata
  • Performance: thread-safe, fast and robust, 32- and 64-bit
  • Lean stand-alone product without side effects
  • Automatic language/script detection
  • Actively supported by a dedicated team

EnterprisePDF search
TET PDF IFilter is available in fully thread-safe native 32- and 64-bit versions. You can implement enterprise PDF search solutions with TET PDF IFilter and the following products:

  • Microsoft Office SharePoint Server (MOSS)
  • Microsoft Search Server 2008 and the free Search Server 2008 Express
  • Microsoft SQL Server
  • Microsoft Exchange Server
  • TET PDF IFilter can be used with all other Microsoft and third-party products which support the IFilter interface.

Desktop PDF search
TET PDF IFilter can also be used to implement desktop PDF search, e.g. with the following products:

  • Windows Desktop Search (WDS): integrated in Windows Vista; also available as free add-on for Windows XP
  • Windows Indexing Service

Accepted PDF input
TET PDF IFilter supports all relevant flavors of PDF input:

  • PDF 1.0 up to PDF 1.7 extension level 8 and PDF 2.0, corresponding to Acrobat 1-XI
  • Encrypted PDFs which do not require a password for opening the document
  • Damaged PDF documents will be repaired if possible

XMP Document Metadata and Document Info Entries

The advanced metadata implementation in TET PDF IFilter supports the Windows property system for metadata. It indexes XMP metadata (Adobe’s rich XML-based metadata description language) as well as standard or custom document info entries. Metadata indexing can be configured on several levels:

  • Document info entries, Dublin Core fields and other common XMP properties are mapped to equivalent Windows properties, e.g. Title, Subject, Author
  • TET PDF IFilter adds useful PDF-specific pseudo properties, e.g. page size, PDF/A conformance level, font names
  • All relevant predefined XMP properties can be searched, e.g. dc:rights, xmpRights:UsageTerms, xmp:CreatorTool
  • User-defined XMP properties can be searched, e.g. company-specific classification properties, PDF/A extension schemas
  • XMP metadata attached to individual images on PDF pages can be indexed, and image-related XMP properties can be used for searching
  • TET PDF IFilter optionally integrates metadata in the full text index. As a result, even full text search engines without metadata support (e.g. SQL Server) can search for metadata

XMP Image Metadata
In addition to document metadata, TET PDF IFilter also supports XMP metadata attached to individual images. In modern workflows metadata travels with the image, e.g. from the digital camera to Photoshop editing up to page layout creation and PDF production. TET PDF IFilter picks up XMP image meta­data and makes it available for searches. For example, you can search for documents which contain images from a certain category, images created by a specific photographer, etc.

Internationalization
TET PDF IFilter includes full support for extracting Chinese, Japanese, and Korean (CJK) text. All CJK encodings are recognized; horizontal and vertical writing modes are supported. Automatic detection of the locale ID (language and region identifier) of the text improves the results of Microsoft’s word breaking and stemming algorithms, which is especially important for East Asian text.

PDF is more than just a Bunch of Pages
TET PDF IFilter treats PDF documents as containers which may contain much more information than only plain pages. TET PDF IFilter indexes all relevant items in PDF documents:

  • Page contents
  • Text in bookmarks
  • Embedded PDFs are processed recursively so that also the text in attached PDF documents can be searched.
  • All documents in a PDF package are indexed. PDF packages are an Acrobat 8 feature for grouping multiple documents in a single PDF file (in Acrobat 9 called portfolios)