PDFlib Text Extraction Toolkit (TET) Manual

numerical glyph names created by various common applications and drivers. Since the
same glyph names may be created for different encodings you can provide the
encodinghint option to TET_open_document( ) in order to specify the target encoding for
schematic glyph names encountered in the document. For example, if you know that
the document contains Russian text, but the text cannot successfully be extracted for
lack of information in the PDF, you can supply the option encodinghint= cp1250 to specify
a Cyrillic codepage.
In addition to the builtin rules for interpreting numerical glyph names you can define
custom rules with the fontname and glyphrule suboptions of the glyphmapping option
of TET_open_document( ). You must supply the following pieces of information:
> The full or abbreviated name of the font to which the rule will be applied (fontname
option)
> A prefix for the glyph names, i.e. the characters before the numerical part (prefix suboption)
> The base (decimal or hexadecimal) in which the numbers will be interpreted (base
suboption)
> The encoding in which to interpret the resulting numerical codes (encoding suboption)
For example, if you determined (e.g. using PDFlib FontReporter) that the glyphs in the
fonts T1, T2, T3, etc. are named c00, c01, c02, ..., cFF where each glyph name corresponds to
the WinAnsi character at the respective hexadecimal position (00, ..., FF) use the following
option for TET_open_document( ):
glyphmapping {{fontname=T* glyphrule={prefix=c base=hex encoding=winansi} }}
External font files and system fonts. If a PDF does not contain sufficient information
for Unicode mapping and the font is not embedded, you can configure additional font
data which TET will use to derive Unicode mappings. Font data may come from a True-
Type or OpenType font file on disk, which can be configure with the fontoutline resource
category. As an alternative on Mac and Windows systems, TET can access fonts which
are installed on the host operating system. Access to these host fonts can be disabled
with the usehostfonts option in TET_open_document( ).
In order to configure a disk file for the WarnockPro font use the following call:
TET_set_option(tet, "fontoutline {WarnockPro WarnockPro.otf}");
See Section 5.2, »Resource Configuration and File Searching«, page 51, for more details
on configuring external font files.
80 Chapter 6: Text Extraction