unicharset_extractor [--output_unicharset filename] [--norm_mode mode] box_or_text_file […]
Where mode means: 1=combine graphemes (use for Latin and other simple scripts) 2=split graphemes (use for Indic/Khmer/Myanmar) 3=pure unicode (use for Arabic/Hebrew/Thai/Tibetan)
Tesseract needs to know the set of possible characters it can output. To generate the unicharset data file, use the unicharset_extractor program on training pages bounding box files or a plain text file:
unicharset_extractor fontfile_1.box fontfile_2.box ...
The unicharset will be put into the file ./unicharset if no output filename is provided.
NOTE Use the appropriate norm_mode based on the language.
tesseract(1), unicharset(5)