GNU Ocrad is an OCR (Optical Character Recognition) program implemented
as a filter and based on a feature extraction method. It reads a bitmap
image in pbm format and outputs text in ISO-8859-1 (Latin-1) charset.
Also includes a layout analyser able to separate the columns or blocks
of text normally found on printed pages.
It can be used as a stand-alone console application, or as a backend to
other programs.

WWW: https://www.gnu.org/software/ocrad/ocrad.html
