> all functions of an OCR engine outside of character recognition per se Actually, depending upon how 'obfuscated' an author was attempting to be, you might ne

> all functions of an OCR engine outside of character recognition per se Actually, depending upon how 'obfuscated' an author was attempting to be, you might need that OCR engine itself. PDF allows for defining arbitrary mappings from byte values to font glyphs. So one could define byte value 32 (decimal, usually ASCII space) to actually map to printing, say, a capitol letter Z instead. One is supposed to provide a reverse mapping table when one does this that says "a decimal 32 byte prints a capitol letter Z" to allow for search and extraction purposes. But the PDF spec. does not require this reverse table be present. So it is quite possible to randomly assign font glyphs to arbitrary byte values, and omit the reverse mapping table. The result would be that extracting data back out of that PDF results in garbage if one does not know beforehand what the mapping from byte value to glyph was. So, if a 'bad actor' did this, one's only recourse to retrieving data would be to rasterize the PDF to a bitmap, then OCR the resulting bitmap to extract the content back out.