PDFlib Text Extraction Toolkit (TET) Manual

9.2 Controlling TETML Details
TETML text modes. TETML can be generated in various text modes which include different
amounts of font and geometry information, and differ regarding the grouping of
text into larger units (granularity). The text mode can be specified individually for each
page. However, in most situations TETML files will contain the data for all pages in the
same mode. The following text modes are available:
> Glyph mode is a low-level flavor which includes the text, font, and coordinates for
each glyph, without any word grouping or structure information. It is intended for
debugging and analysis purposes since it represents the original text information on
the page.
> Word mode groups text into words and adds Box elements with the coordinates of
each word. No font information is available. This mode is suitable for applications
which operate on word basis. Punctuation characters will by default be treated as individual
words, but this behavior can be changed with a page option (see »Word
boundary detection for Western text«, page 85). Lines of text can optionally be identified
with the Line element; this is controlled via the tetml page option.
> Wordplus mode is similar to word mode, but adds font and coordinate details for all
glyphs in a word. The coordinates are expressed relative to the lower left or upper
left corner subject to the topdown page option. Wordplus mode makes it possible to
analyze font usage and track changes of font, font size, etc. within a word. Since
wordplus is the only text mode which contains all relevant TETML elements it is suited
for all kinds of processing tasks. On the other hand, it creates the largest amount
of output due to the wealth of information contained in the TETML.
> Line mode includes all text which comprises a line in a separate Line element. In addition,
multiple lines may be grouped in a Para element. Line mode is recommended
only in situations where the page content is known to be grouped into lines, or the
receiving application can only deal with line-based text input.
> Page mode includes structure information starting at the paragraph level, but does
not include any font or coordinate details.
Table 9.1 lists the TETML elements which are present in the text modes.
Table 9.1 TETML elements in various text mode
text mode structure tables text position text details
glyph – – – Glyph
word
wordplus
Para, Word
optionally: Line
Para, Word
optionally: Line
Table, Row, Cell Box –
Table, Row, Cell Box Glyph
line Para, Line – – –
page Para Table, Row, Cell – –
Selecting the text mode. With the TET command-line tool (see Section 2.1, »Command-Line
Options«, page 17) you can specify the desired page mode as a parameter for
the --tetml option. The following command generates TETML output in wordplus mode:
9.2 Controlling TETML Details 127