read-PNM-error: file number is 0, position -1 read-PNM-error: bad magic bytes, expect 0x50 0x3[1-6] but got 0xff 0xff

Optical Character Recognition --- gocr 0.49 20100924 Copyright (C) 2001-2010 Joerg Schulenburg GPG=1024D/53BDFBE3 released under the GNU General Public License using: gocr [options] pnm_file_name # use - for stdin options (see gocr manual pages for more details): -h, --help -i name - input image file (pnm,pgm,pbm,ppm,pcx,...) -o name - output file (redirection of stdout) -e name - logging file (redirection of stderr) -x name - progress output to fifo (see manual) -p name - database path including final slash (default is ./db/) -f fmt - output format (ISO8859_1 TeX HTML XML UTF8 ASCII) -l num - threshold grey level 0<160<=255 (0 = autodetect) -d num - dust_size (remove small clusters, -1 = autodetect) -s num - spacewidth/dots (0 = autodetect) -v num - verbose (see manual page) -c string - list of chars (debugging, see manual) -C string - char filter (ex. hexdigits: 0-9A-Fx, only ASCII) -m num - operation modes (bitpattern, see manual) -a num - value of certainty (in percent, 0..100, default=95) -u string - output this string for every unrecognized character examples: gocr -m 4 text1.pbm # do layout analyzis gocr -m 130 -p ./database/ text1.pbm # extend database djpeg -pnm -gray text.jpg | gocr - # use jpeg-file via pipe webpage: http://jocr.sourceforge.net/