com.itextpdf.pdfocr.tesseract4

Class AbstractTesseract4OcrEngine

java.lang.Object

com.itextpdf.pdfocr.tesseract4.AbstractTesseract4OcrEngine

All Implemented Interfaces:

IThreadLocalMetaInfoAware, IOcrEngine

Direct Known Subclasses:

Tesseract4ExecutableOcrEngine, Tesseract4LibOcrEngine

public abstract class AbstractTesseract4OcrEngine
extends Object
implements IOcrEngine, IThreadLocalMetaInfoAware

The implementation of IOcrEngine. This class provides possibilities to perform OCR, to read data from input files and to return contained text in the required format. Also there are possibilities to use features of "tesseract" (optical character recognition engine for various operating systems).

Constructor Summary

Constructors

Constructor and Description
AbstractTesseract4OcrEngine(Tesseract4OcrEngineProperties tesseract4OcrEngineProperties)

Method Summary

Modifier and Type	Method and Description
void	createTxtFile(List<File> inputImages, File txtFile) Performs OCR using provided IOcrEngine for the given list of input images and saves output to a text file using provided path.
Map<Integer,List<TextInfo>>	doImageOcr(File input) Reads data from the provided input image file and returns retrieved data in the format described below.
String	doImageOcr(File input, OutputFormat outputFormat) Reads data from the provided input image file and returns retrieved data as string.
void	doTesseractOcr(File inputImage, File outputFile, OutputFormat outputFormat) Performs tesseract OCR for the first (or for the only) image page.
String	getLanguagesAsString() Gets list of languages concatenated with "+" symbol to a string in format required by tesseract.
Tesseract4OcrEngineProperties	getTesseract4OcrEngineProperties() Gets properties for AbstractTesseract4OcrEngine.
com.itextpdf.kernel.counter.event.IMetaInfo	getThreadLocalMetaInfo() Gets the meta info which is held by the interface.
String	identifyOsType() Identifies type of current OS and return it (win, linux).
boolean	isWindows() Checks current os type.
void	setTesseract4OcrEngineProperties(Tesseract4OcrEngineProperties tesseract4OcrEngineProperties) Sets properties for AbstractTesseract4OcrEngine.
IThreadLocalMetaInfoAware	setThreadLocalMetaInfo(com.itextpdf.kernel.counter.event.IMetaInfo metaInfo) Sets a thread local meta info.
void	validateLanguages(List<String> languagesList) Validates list of provided languages and checks if they all exist in given tess data directory.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractTesseract4OcrEngine

public AbstractTesseract4OcrEngine(Tesseract4OcrEngineProperties tesseract4OcrEngineProperties)

Method Detail

doTesseractOcr

public void doTesseractOcr(File inputImage,
                           File outputFile,
                           OutputFormat outputFormat)

Performs tesseract OCR for the first (or for the only) image page.

Parameters:

inputImage - input image File

outputFile - output file for the result for the first page

outputFormat - selected OutputFormat for tesseract

createTxtFile

public void createTxtFile(List<File> inputImages,
                          File txtFile)

Performs OCR using provided IOcrEngine for the given list of input images and saves output to a text file using provided path.

Specified by:

createTxtFile in interface IOcrEngine

Parameters:

inputImages - List of images to be OCRed

txtFile - file to be created

getTesseract4OcrEngineProperties

public final Tesseract4OcrEngineProperties getTesseract4OcrEngineProperties()

Gets properties for AbstractTesseract4OcrEngine.

Returns:

set properties Tesseract4OcrEngineProperties

setTesseract4OcrEngineProperties

public final void setTesseract4OcrEngineProperties(Tesseract4OcrEngineProperties tesseract4OcrEngineProperties)

Sets properties for AbstractTesseract4OcrEngine.

Parameters:

tesseract4OcrEngineProperties - set of properties Tesseract4OcrEngineProperties for AbstractTesseract4OcrEngine

getLanguagesAsString

public final String getLanguagesAsString()

Gets list of languages concatenated with "+" symbol to a string in format required by tesseract.

Returns:

String of concatenated languages

doImageOcr

public final Map<Integer,List<TextInfo>> doImageOcr(File input)

Reads data from the provided input image file and returns retrieved data in the format described below.

Specified by:

doImageOcr in interface IOcrEngine

Parameters:

input - input image File

Returns:

Map where key is Integer representing the number of the page and value is List of TextInfo elements where each TextInfo element contains a word or a line and its 4 coordinates(bbox)

doImageOcr

public final String doImageOcr(File input,
                               OutputFormat outputFormat)

Reads data from the provided input image file and returns retrieved data as string.

Parameters:

input - input image File

outputFormat - return OutputFormat result

Returns:

OCR result as a String that is returned after processing the given image

isWindows

public boolean isWindows()

Checks current os type.

Returns:

boolean true is current os is windows, otherwise - false

identifyOsType

public String identifyOsType()

Identifies type of current OS and return it (win, linux).

Returns:

type of current os as String

validateLanguages

public void validateLanguages(List<String> languagesList)
                       throws Tesseract4OcrException

Validates list of provided languages and checks if they all exist in given tess data directory.

Parameters:

languagesList - List of provided languages

Throws:

Tesseract4OcrException - if tess data wasn't found for one of the languages from the provided list

getThreadLocalMetaInfo

public com.itextpdf.kernel.counter.event.IMetaInfo getThreadLocalMetaInfo()

Gets the meta info which is held by the interface.

Specified by:

getThreadLocalMetaInfo in interface IThreadLocalMetaInfoAware

Returns:

the held thread local meta info

setThreadLocalMetaInfo

public IThreadLocalMetaInfoAware setThreadLocalMetaInfo(com.itextpdf.kernel.counter.event.IMetaInfo metaInfo)

Sets a thread local meta info.

Specified by:

setThreadLocalMetaInfo in interface IThreadLocalMetaInfoAware

Parameters:

metaInfo - a thread local meta info to be held

Returns:

this IThreadLocalMetaInfoAware