PDFlib Text Extraction Toolkit (TET) Manual

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PDF packages and portfolios. Acrobat 8 (PDF 1.7) introduced the concept of PDF packages which are file attachments with additional properties. Acrobat 9 (PDF 1.7 extension level 3) extends this concept with the introduction of PDF portfolios. > How to display with Acrobat 8/9: Acrobat presents the cover sheet of the package/ portfolio and the constituent PDF documents with dedicated user interface elements for PDF packages. > How to search a single PDF package with Acrobat 8/9: Edit, Search and in the Look In: pull-down select In the Entire PDF Package > How to search multiple PDF packages with Acrobat 8/9: not available > Sample code for the TET library: get_attachments mini sample > TETML element: /TET/Document/Attachments/Attachment/Document PDF properties. This domain does not explicitly contain text, but is used as a pseudo domain which collects various intrinsic properties of a PDF document, e.g. PDF/X and PDF/A status, Tagged PDF status, etc. > How to display with Acrobat 8: Acrobat 8 does not directly display standards conformance information, but you can find relevant entries in File, Properties..., Custom or File, Properties..., Additional Metadata... You can also use the free PDFlib custom XMP panel 1 for ISO standards to explicitly display conformance information for the PDF/A-1, PDF/X-4, PDF/X-5, and PDF/E-1 standards. > Acrobat 9: View, Navigation Panels, Standards (only present for standard-conforming PDFs) > How to search with Acrobat 8/9: not available > Sample code for the TET library: dumper mini sample > TETML elements and attributes: /TET/Document/@pdfa, /TET/Document/@pdfx 1. See www.pdflib.com/developer/xmp-metadata/xmp-panels 60 Chapter 6: Text Extraction
6.2 Unicode Concepts Unicode encoding forms (UTF formats). The Unicode standard assigns a number (code point) to each character. In order to use these numbers in computing, they must be represented in some way. In the Unicode standard this is called an encoding form (formerly: transformation format); this term should not be confused with font encodings. Unicode defines the following encoding forms: > UTF-8: This is a variable-width format where code points are represented by 1-4 bytes. ASCII characters in the range U+0000...U+007F are represented by a single byte in the range 00...7F. Latin-1 characters in the range U+00A0...U+00FF are represented by two bytes, where the first byte is always 0xC2 or 0xC3 (these values represent Â and Ã in Latin-1). > UTF-16: Code points in the Basic Multilingual Plane (BMP), i.e. characters in the range U+0000...U+FFFF are represented by a single 16-bit value. Code points in the supplementary planes, i.e. in the range U+10000...U+10FFFF, are represented by a pair of 16- bit values. Such pairs are called surrogate pairs. A surrogate pair consists of a highsurrogate value in the range D800...DBFF and a low-surrogate value in the range DC00...DFFF. High- and low-surrogate values can only appear as parts of surrogate pairs, but not in any other context. > UTF-32: Each code point is represented by a single 32-bit value. The Byte Order Mark (BOM). Computer architectures differ in the ordering of bytes, i.e. whether the bytes constituting a larger value (16- or 32-bit) are stored with the most significant byte first (big-endian) or the least significant byte first (little-endian). A common example for big-endian architectures is PowerPC, while the x86 architecture is little-endian. Since UTF-8 and UTF-16 are based on values which are larger than a single byte, the byte-ordering issue comes into play here. An encoding scheme (note the difference to encoding form above) specifies the encoding form plus the byte ordering. For example, UTF-16BE stands for UTF-16 with big-endian byte ordering. If the byte ordering is not known in advance it can be specified by means of the code point U+FEFF, which is called Byte Order Mark (BOM). Although a BOM is not required in UTF-8, it may be present as well, and can be used to identify a stream of bytes as UTF-8. Table 6.1 lists the representation of the BOM for various encoding forms. Table 6.1 Byte order marks for various Unicode encoding forms Encoding form Byte order mark (hex) graphical representation UTF-8 EF BB BF ï»¿ UTF-16 big-endian FE FF þÿ UTF-16 little-endian FF FE ÿþ UTF-32 big-endian 00 00 FE FF ? ? þÿ 1 UTF-32 little-endian FF FE 00 00 ÿþ ? ? 1 1. There is no standard graphical representation of null bytes. 6.2 Unicode Concepts 61
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PDFlib GmbH München, Germany www.p
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Contents 0 First Steps with TET 7 0
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10.9 Option Handling 151 10.10 pCOS
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0.2 Applying the TET License Key Us
Page 11 and 12: 1 Introduction The PDFlib Text Extr
Page 13 and 14: may extract some text which is not
Page 15 and 16: 2 TET Command-Line Tool 2.1 Command
Page 17 and 18: Constructing TET command lines. The
Page 19 and 20: Extract images and generate TETML i
Page 21 and 22: 3 TET Library Language Bindings Thi
Page 23 and 24: TET_CATCH(tet) { printf("Error %d i
Page 25 and 26: 3.4 COM Binding Installing the TET
Page 27 and 28: 3.6 .NET Binding The .NET edition o
Page 29 and 30: 3.8 PHP Binding Installing the TET
Page 31 and 32: 3.9 Python Binding Installing the T
Page 33 and 34: Exception Handling in RPG. TET clie
Page 35 and 36: 4 TET Connectors TET connectors pro
Page 37 and 38: 4.2 TET Connector for the Lucene Se
Page 39 and 40: Indexing metadata fields. The TET c
Page 41 and 42: 4.4 TET Connector for Oracle The TE
Page 43 and 44: these options on the command line.
Page 45 and 46: TET PDF IFilter is freely available
Page 47 and 48: tracts text and metadata from the P
Page 49 and 50: 5 Configuration 5.1 Indexing protec
Page 51 and 52: 5.2 Resource Configuration and File
Page 53 and 54: tet/3.0/resource /tet/3.0/resource/
Page 55 and 56: Geometry. The geometry features may
Page 57 and 58: 6 Text Extraction 6.1 Document Doma
Page 59: How to search with Acrobat 8/9: not
Page 63 and 64: artificial characters which will be
Page 65 and 66: width (x, y) beta fontsize baseline
Page 67 and 68: 6.4 Support for Chinese, Japanese,
Page 69 and 70: Options for text filtering. There a
Page 71 and 72: 6.6 Content Analysis PDF documents
Page 73 and 74: Dehyphenation. Hyphenated words at
Page 75 and 76: Table 6.3 Document styles docstyle=
Page 77 and 78: Fig. 6.5 Sample font reports create
Page 79 and 80: glyphmapping {{fontname=Warnock* to
Page 81 and 82: 7 Image Extraction 7.1 Image Extrac
Page 83 and 84: 7.2 Image Geometry Using TET_get_im
Page 85 and 86: 7.3 Image Analysis Image merging. S
Page 87 and 88: 7.4 Restrictions and Caveats Image
Page 89 and 90: 8 TET Markup Language (TETML) 8.1 C
Page 91 and 92: Depending on the sele
Page 93 and 94: You can specify the amount of text
Page 95 and 96: Table 8.3 TETML elements TETML elem
Page 97 and 98: 8.4 Transforming TETML with XSLT Ve
Page 99 and 100: Run the program as follows: nxslt3.
Page 101 and 102: 8.5 XSLT Samples The TET distributi
Page 103 and 104: Alphabetical list of words in the d
Page 105 and 106: 9 The pCOS Interface The pCOS (PDFl
Page 107 and 108: 9.2 Handling Basic PDF Data Types p
Page 109 and 110: 9.3 Composite Data Structures and I
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Path prefixes. Prefixes can be used
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Table 9.3 Universal pseudo objects
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Table 9.4 Pseudo objects for PDF ob
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Table 9.5 Pseudo objects for resour
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9.6 Encrypted PDF Documents pCOS su
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10 TET Library API Reference 10.1 O
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10.2 General Functions Perl PHP res
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Returns Scope Bindings The converte
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10.3 Exception Handling C++ string
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10.4 Document Functions C++ int ope
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Table 10.3 Document options for TET
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C++ C int open_document_callback(vo
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Table 10.5 Page options for TET_ope
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Table 10.6 Suboptions for the conte
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Table 10.7 Suboptions for the layou
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Table 10.9 Suboptions for the struc
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C++ const TET_char_info *get_char_i
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10.7 Image Retrieval Functions C++
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C++ int write_image_file(int doc, i
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10.8 TET Markup Language (TETML) Fu
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10.9 Option Handling C++ void set_o
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10.10 pCOS Functions The full pCOS
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If the object has type stream all f
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A TET Library Quick Reference The f
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B Revision History Revision history
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unsupported types 87 XMP metadata 8
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