Package 'kwb.gocr'

Title: Interface to gocr Program
Description: Wrapper functions to the gocr (Optical Character Recognition) program developed by Jens Schulenberg (https://www-e.ovgu.de/jschulen/ocr/).
Authors: Hauke Sonnenberg [aut, cre] (ORCID: <https://orcid.org/0000-0001-9134-2871>), Michael Rustler [ctb] (ORCID: <https://orcid.org/0000-0003-0647-7726>), FAKIN [fnd], MIA-CSO [fnd], Kompetenzzentrum Wasser Berlin gGmbH (KWB) [cph]
Maintainer: Hauke Sonnenberg <[email protected]>
License: MIT + file LICENSE
Version: 0.1.0
Built: 2026-05-24 07:57:13 UTC
Source: https://github.com/KWB-R/kwb.gocr

Help Index

Create a gocr Configuration

Description

Create a gocr Configuration

Usage

gocrConfig(
  inputfile,
  showhelp = FALSE,
  outputfile = "",
  errorfile = "",
  progressfile = "",
  databasepath = "",
  outputformat = "",
  greylevel = 0,
  dustsize = -1,
  spacewidth = 0,
  verbosity = 0,
  limitVerbosityToChars = "",
  limitRecognitionToChars = "",
  certainty = 95,
  mode = 0,
  onlyRecogniseNumbers = FALSE
)

Arguments

inputfile

-i file: read input from file (or stdin if file is a single dash)
showhelp

-h: show usage information
outputfile

-o file: send output to file instead of stdout. If "" (default), a file "gocrOut_<basename(outputfile)>" in tempdir() is used as the output file.
errorfile

-e file: send errors to file instead of stderr or to stdout if file is a dash
progressfile

-x file: progress output to file (file can be a file name, a fifo name or a file descriptor 1...255), this is useful for GUI developpers to show the OCR progress, the file descriptor argument is only available, if compiled with __USE_POSIX defined
databasepath

-p path: database path, that will be populated with images of learned characters. If "" (default), and a database is needed, a directory within the folder of the installed package is used
outputformat

-f format: output format of the recognized text (ISO8859_1 TeX HTML XML UTF8 ASCII), XML will also output position and probability data
greylevel

-l level set grey level to level (0<160<=255, default: 0 for autodetect), darker pixels belong to characters, brighter pixels are inter- preted as background of the input image
dustsize

-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
spacewidth

-s num: set spacewidth between words in units of dots (default: 0 for autodetect), wider widths are interpreted as word spaces, smaller as character spaces
verbosity

-v verbosity: be verbose to stderr; verbosity is a bitfield. Use optionValueVerbosity to get a proper value
limitVerbosityToChars

-c string: only verbose output of characters from string to stderr, more output is generated for all characters within the string, the
limitRecognitionToChars

-C string: only recognise characters from string, this is a filter function in cases where the interest is only to a part of the character alphabet
certainty

-a certainty: set value for certainty of recognition (0..100; default: 95), characters with a higher certainty are accepted, characters with a lower certainty are treated as unknown (not recognized); set higher values, if you want to have only more certain recognized characters
mode

-m mode: set oprational mode; mode is a bitfield (default: 0). Use optionValueMode to get a proper value
onlyRecogniseNumbers

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

Download gocr executable

Description

Download gocr executable

Usage

gocrDownload(
  version_number = "048",
  overwrite = FALSE,
  target_dir = file.path(system.file(package = "kwb.gocr"), "extdata/gocr")
)

Arguments

version_number

latest version number is "049". However, "048" was used for the development of this R package and is still available (default: "048")
overwrite

if TRUE downloads and overwrites existing gocr executable in target_directory, otherwise not (default: FALSE)
target_dir

target directory (default: file.path(system.file(package = "kwb.gocr"), "extdata/gocr2")

Value

downloads gocr executable to target directory and returns path

Examples

gocrDownload(version_number = "048")
## Not run: 
gocrDownload(version_number = "049")

## End(Not run)

Path to gocr Executable File

Description

Path to gocr Executable File

Usage

gocrExePath()

Option String for gocr Call

Description

Option String for gocr Call

Usage

gocrOptionString(config)

Arguments

config

gocr configuration as returned by gocrConfig

Run gocr on an Image File

Description

Run gocr on an Image File

Usage

gocrRun(
  config,
  useBatch = TRUE,
  waitForBatch = TRUE,
  opendir = TRUE,
  dbg = TRUE
)

Arguments

config

gocr configuration as returned by gocrConfig
useBatch

if TRUE (default), a batch file is written so that the user can reproduce the call by double-clicking the batch file in the file explorer (opens when opendir is TRUE)
waitForBatch

passed to kwb.gocr:::writeAndRunBatchFile
opendir

if TRUE (default), and if useBatch is TRUE, the directory in which the batch file is written, is opened in the Windows Explorer
dbg

if TRUE debug messages are shown

Value

(only if waitForBatch = TRUE): result of OCR as a vector of character representing the recognised lines. The result vector has the attribute config containing the configuration used (original config, with default values set where needed)

Value for Mode Option

Description

Value for Mode Option

Usage

optionValueMode(
  useDatabase = FALSE,
  layoutAnalysis = FALSE,
  doNotCompare = FALSE,
  doNotDivide = FALSE,
  doNotCorrect = FALSE,
  characterPacking = FALSE,
  extendDatabase = FALSE,
  switchOffEngine = FALSE
)

Arguments

useDatabase

(2) use database to recognize characters which are not recognized by other algorithms, (early development)
layoutAnalysis

(4) switching on layout analysis or zoning (development)
doNotCompare

(8) don't compare unrecognized characters to recognized one
doNotDivide

(16) don't try to divide overlapping characters to two or three single characters
doNotCorrect

(32) don't do context correction
characterPacking

(64) character packing, before recognition starts, similar characters are searched and only one of this characters will be send to the recognition engine (development)
extendDatabase

(128) extend database, prompts user for unidentified characters and extends the database with users answer (128+2, early development)
switchOffEngine

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

References

http://manpages.ubuntu.com/manpages/gutsy/man1/gocr.1.html

Value for Option Verbosity

Description

Value for Option Verbosity

Usage

optionValueVerbosity(
  printMore = 1,
  listShapes = 1,
  listPattern = 1,
  printPattern = 1,
  printDebug = 1,
  createOutPng = 0
)

Arguments

printMore

(1) print more info
listShapes

(2) list shapes of boxes (see -c) to stderr
listPattern

(4) list pattern of boxes (see -c) to stderr
printPattern

(8) print pattern after recognition for debugging
printDebug

(16) print debug information about recognition of lines to stderr
createOutPng

(32) create outXX.png with boxes and lines marked on each general OCR-step