1OCRAD(1) User Commands OCRAD(1)
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6 ocrad - command line text recognition tool
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9 ocrad [options] [files]
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12 GNU Ocrad is an OCR (Optical Character Recognition) program based on a
13 feature extraction method. It reads images in png or pnm formats and
14 produces text in byte (8-bit) or UTF-8 formats. The formats pbm (bit‐
15 map), pgm (greyscale), and ppm (color) are collectively known as pnm.
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17 Ocrad includes a layout analyser able to separate the columns or blocks
18 of text normally found on printed pages.
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20 For best results the characters should be at least 20 pixels high. If
21 they are smaller, try the option --scale. Scanning the image at 300 dpi
22 usually produces a character size good enough for ocrad. Merged, very
23 bold, or very light (broken) characters are normally not recognized
24 correctly. Try to avoid them.
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27 -h, --help
28 display this help and exit
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30 -V, --version
31 output version information and exit
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33 -a, --append
34 append text to output file
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36 -c, --charset=<name>
37 try '--charset=help' for a list of names
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39 -e, --filter=<name>
40 try '--filter=help' for a list of names
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42 -E, --user-filter=<file>
43 user-defined filter, see manual for format
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45 -f, --force
46 force overwrite of output file
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48 -F, --format=<fmt>
49 output format (byte, utf8)
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51 -i, --invert
52 invert image levels (white on black)
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54 -l, --layout
55 perform layout analysis
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57 -o, --output=<file>
58 place the output into <file>
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60 -q, --quiet
61 suppress all messages
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63 -s, --scale=[-]<n>
64 scale input image by [1/]<n>
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66 -t, --transform=<name>
67 try '--transform=help' for a list of names
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69 -T, --threshold=<n>
70 threshold for binarization (0.0-1.0)
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72 -u, --cut=<l,t,w,h>
73 cut the input image by the rectangle given
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75 -v, --verbose
76 be verbose
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78 -x, --export=<file>
79 export results in ORF format to <file>
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81 If no files are specified, or if a file is '-', ocrad reads the image
82 from standard input. If the option -o is not specified, ocrad sends
83 text to standard output.
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85 Exit status: 0 for a normal exit, 1 for environmental problems (file
86 not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or
87 invalid input file, 3 for an internal consistency error (e.g., bug)
88 which caused ocrad to panic.
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91 Report bugs to bug-ocrad@gnu.org
92 Ocrad home page: http://www.gnu.org/software/ocrad/ocrad.html
93 General help using GNU software: http://www.gnu.org/gethelp
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96 Copyright © 2022 Antonio Diaz Diaz. License GPLv2+: GNU GPL version 2
97 or later <http://gnu.org/licenses/gpl.html>
98 This is free software: you are free to change and redistribute it.
99 There is NO WARRANTY, to the extent permitted by law.
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102 The full documentation for ocrad is maintained as a Texinfo manual. If
103 the info and ocrad programs are properly installed at your site, the
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106 info ocrad
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108 should give you access to the complete manual.
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112GNU ocrad 0.28 January 2022 OCRAD(1)