gocr - command line OCR tool

gocr [OPTION] [-i] pnm file

gocr is an optical character recognition program that can be used from the command line. It takes input in PNM, PGM, PBM, PPM, or PCX format, and writes recognized text to stdout. If the pnm file is a single dash, PNM data is read from stdin. If gzip, bzip2 and netpbm-progs are installed and your system supports popen(3) also pnm.gz, pnm.bz2, png, jpg, jpeg, tiff, gif, bmp, ps (only single pages) and eps are supported as input files (not as input stream), where pnm can be replaced by one of ppm, pgm and pbm.

-h

show usage information

-i file

read input from file (or stdin if file is a single dash)

-o file

send output to file instead of stdout

-e file

send errors to file instead of stderr or to stdout if file is a dash

-x file

progress output to file (file can be a file name, a fifo name or a file descriptor 1...255)

-p path

database path (including final slash, default is ./db/)

-f format

output format (ISO8859_1 TeX HTML UTF8 ASCII)

-l level

set grey level to level (0<160<=255, default: 0 for autodetect)

-d size

set dust size in pixels (clusters smaller than this are removed), 0 means no clusters are removed, the default is -1 for auto detection

-s num

set spacewidth/dots (default: 0 for autodetect)

-v verbosity

be verbose; verbosity is a bitfield

-c string

only verbose output of characters from string

-C string

only recognise characters from string

-m modes

set operation modes; modes is a bitfield

-n bool

if bool is non-zero, only recognise numbers (this is now obsolete, use -C "0123456789")

The verbosity is specified as a bitfield:

1

print more info

2

list shapes of boxes (see -c)

4

list pattern of boxes (see -c)

8

print pattern after recognition

16

print line information

32

create outXX.pgm

The operation modes are:

2

use database (early development)

4

layout analysis, zoning (development)

8

don't compare unrecognized characters

16

don't divide overlapping characters

32

don't do context correction

64

character packing (development)

130

extend database, prompts user (128+2, early development)

256

switch off the OCR engine (makes sense together with -m 2)

Joerg Schulenburg <jschulen@gmx.de>

First version of man page by Tim Waugh <twaugh@redhat.com>

This man page documents gocr, version 0.37.

Report bugs to <jschulen@gmx.de>

More details can be found at /usr/share/doc/gocr-X.XX/gocr.html.

gocr -v 33 text1.pbm

output verbose information, out30.bmp is created to see details of recognition process

gocr -v 7 -c _YV text1.pbm

verbose output for unknown chars and chars Y and V

djpeg -pnm -gray text.jpg | gocr -

convert a jpeg file to pnm format and input via pipe