I downloaded deu_frak.traineddata Fraktur.traineddata and frk.traineddata to usr/loca/share/tessdata. But when using
$ tesseract file.tiff -l Fraktur Fraktur I get the error message Error opening data file ./tessdata/Fraktur.traineddata Please make sure the TESSDATA_PREFIX environment variable is set to the parent directory of your "tessdata" directory. Failed loading language 'Fraktur' Tesseract couldn't load any languages! Could not initialize tesseract. -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. To unsubscribe from this group and stop receiving emails from it, send an email to tesseract-ocr+unsubscr...@googlegroups.com. To post to this group, send email to tesseract-ocr@googlegroups.com. Visit this group at https://groups.google.com/group/tesseract-ocr. To view this discussion on the web visit https://groups.google.com/d/msgid/tesseract-ocr/e190c5c4-9099-4077-98a8-bf03802e509d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
