 <p>Glyph ID's do not always correspond to Unicode character values - especially with non latin scripts that use a lot of ligatures and variant glyph forms where there is not a one-to-one correspondance between glyphs and characters.</p> <p>Only Tagged PDF files store the Unicode text - otherwise you may have to reconstruct the characters from the glyph names in the fonts. This is possible if the fonts used have glyphs named according to Adobe's Glyph Naming Convention or <a href="http://sourceforge.net/adobe/aglfn/wiki/AGL%20Specification/" rel="nofollow">Adobe Glyph List Specification</a> - but many fonts, including the standard Windows fonts, don't follow this naming convention.</p>