I tried Strucurise's free "Kleptomania 2.1" trial (www.structurise.com) to
grab text from a PDF with disabled text copy&paste feature.
(Kleptomania is a special OCR-program which "reverse engineers texts" from
bitmap pictures, i.e.: transforms pixels back into ASCII-chars)
Disabling anti-aliasing in Acrobat and then experimenting a bit showed that
the recognition rate depends mainly on the PDF's zoom factor (~128% gave
best results), but still the results are not good.
Does anyone know of a better tool?