org.apache.tika.parser.ocr

Class TesseractOCRParser

java.lang.Object

org.apache.tika.parser.AbstractParser

org.apache.tika.parser.AbstractExternalProcessParser

org.apache.tika.parser.ocr.TesseractOCRParser

All Implemented Interfaces:

Serializable, Initializable, Parser

public class TesseractOCRParser
extends AbstractExternalProcessParser
implements Initializable

TesseractOCRParser powered by tesseract-ocr engine. To enable this parser, create a TesseractOCRConfig object and pass it through a ParseContext. Tesseract-ocr must be installed and on system path or the path to its root folder must be provided:

TesseractOCRConfig config = new TesseractOCRConfig();
//Needed if tesseract is not on system path
config.setTesseractPath(tesseractFolder);
parseContext.set(TesseractOCRConfig.class, config);

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Property	IMAGE_MAGICK
static Property	IMAGE_ROTATION
static String	TESS_META

Constructor Summary

Constructors

Constructor and Description
TesseractOCRParser()

Method Summary

Modifier and Type	Method and Description
void	checkInitialization(InitializableProblemHandler problemHandler)
TesseractOCRConfig	getDefaultConfig()
String	getImageMagickPath()
static String	getImageMagickProg()
Set<String>	getLangs()
Set<MediaType>	getSupportedTypes(ParseContext context) Returns the set of media types supported by this parser when used with the given parse context.
String	getTessdataPath()
String	getTesseractPath()
static String	getTesseractProg()
boolean	hasTesseract()
protected boolean	hasWarned()
void	initialize(Map<String,Param> params)
void	parse(Image image, ContentHandler handler, Metadata metadata, ParseContext context)
void	parse(InputStream stream, ContentHandler handler, Metadata metadata, ParseContext parseContext) Parses a document stream into a sequence of XHTML SAX events.
void	setApplyRotation(boolean applyRotation)
void	setColorspace(String colorspace)
void	setDensity(int density)
void	setDepth(int depth)
void	setEnableImagePreprocessing(boolean enableImagePreprocessing)
void	setFilter(String filter)
void	setImageMagickPath(String imageMagickPath) Set the path to the ImageMagick executable directory, needed if it is not on system path.
void	setLanguage(String language)
void	setMaxFileSizeToOcr(long maxFileSizeToOcr)
void	setMinFileSizeToOcr(long minFileSizeToOcr)
void	setOtherTesseractSettings(List<String> settings)
void	setOutputType(String outputType)
void	setPageSegMode(String pageSegMode)
void	setPreloadLangs(boolean preloadLangs) If set to true and if tesseract is found, this will load the langs that result from --list-langs.
void	setPreserveInterwordSpacing(boolean preserveInterwordSpacing)
void	setResize(int resize)
void	setSkipOCR(boolean skipOCR)
void	setTessdataPath(String tessdataPath) Set the path to the 'tessdata' folder, which contains language files and config files.
void	setTesseractPath(String tesseractPath) Set the path to the Tesseract executable's directory, needed if it is not on system path.
void	setTimeout(int timeout)
protected void	warn()

Methods inherited from class org.apache.tika.parser.AbstractExternalProcessParser

register, release

Methods inherited from class org.apache.tika.parser.AbstractParser

parse

Methods inherited from class java.lang.Object

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

Field Detail

TESS_META

public static final String TESS_META

See Also:

Constant Field Values

IMAGE_ROTATION

public static final Property IMAGE_ROTATION

IMAGE_MAGICK

public static final Property IMAGE_MAGICK

Constructor Detail

TesseractOCRParser

public TesseractOCRParser()

Method Detail

getImageMagickProg

public static String getImageMagickProg()

getTesseractProg

public static String getTesseractProg()

getSupportedTypes

public Set<MediaType> getSupportedTypes(ParseContext context)

Description copied from interface: Parser

Returns the set of media types supported by this parser when used with the given parse context.

Specified by:

getSupportedTypes in interface Parser

Parameters:

context - parse context

Returns:

immutable set of media types

hasTesseract

public boolean hasTesseract()
                     throws TikaConfigException

Throws:

TikaConfigException

parse

public void parse(Image image,
                  ContentHandler handler,
                  Metadata metadata,
                  ParseContext context)
           throws IOException,
                  SAXException,
                  TikaException

Throws:

IOException

SAXException

TikaException

parse

public void parse(InputStream stream,
                  ContentHandler handler,
                  Metadata metadata,
                  ParseContext parseContext)
           throws IOException,
                  SAXException,
                  TikaException

Description copied from interface: Parser

Parses a document stream into a sequence of XHTML SAX events. Fills in related document metadata in the given metadata object.

The given document stream is consumed but not closed by this method. The responsibility to close the stream remains on the caller.

Information about the parsing context can be passed in the context parameter. See the parser implementations for the kinds of context information they expect.

Specified by:

parse in interface Parser

Parameters:

stream - the document stream (input)

handler - handler for the XHTML SAX events (output)

metadata - document metadata (input and output)

parseContext - parse context

Throws:

IOException - if the document stream could not be read

SAXException - if the SAX events could not be processed

TikaException - if the document could not be parsed

initialize

public void initialize(Map<String,Param> params)
                throws TikaConfigException

Specified by:

initialize in interface Initializable

Parameters:

params - params to use for initialization

Throws:

TikaConfigException

checkInitialization

public void checkInitialization(InitializableProblemHandler problemHandler)
                         throws TikaConfigException

Specified by:

checkInitialization in interface Initializable

Parameters:

problemHandler - if there is a problem and no custom initializableProblemHandler has been configured via Initializable parameters, this is called to respond.

Throws:

TikaConfigException

getLangs

public Set<String> getLangs()

hasWarned

protected boolean hasWarned()

warn

protected void warn()

getTesseractPath

public String getTesseractPath()

setTesseractPath

@Field
public void setTesseractPath(String tesseractPath)

Set the path to the Tesseract executable's directory, needed if it is not on system path.

Note that if you set this value, it is highly recommended that you also set the path to (and including) the 'tessdata' folder using setTessdataPath(java.lang.String).

getTessdataPath

public String getTessdataPath()

setTessdataPath

@Field
public void setTessdataPath(String tessdataPath)

Set the path to the 'tessdata' folder, which contains language files and config files. In some cases (such as on Windows), this folder is found in the Tesseract installation, but in other cases (such as when Tesseract is built from source), it may be located elsewhere.

Make sure to include the 'tessdata' folder in this path: '/blah/de/blah/tessdata'

getImageMagickPath

public String getImageMagickPath()

setImageMagickPath

@Field
public void setImageMagickPath(String imageMagickPath)

Set the path to the ImageMagick executable directory, needed if it is not on system path.

Parameters:

imageMagickPath - to ImageMagick executable directory.

setOtherTesseractSettings

@Field
public void setOtherTesseractSettings(List<String> settings)
                                      throws TikaConfigException

Throws:

TikaConfigException

setSkipOCR

@Field
public void setSkipOCR(boolean skipOCR)

setLanguage

@Field
public void setLanguage(String language)

setPageSegMode

@Field
public void setPageSegMode(String pageSegMode)

setMaxFileSizeToOcr

@Field
public void setMaxFileSizeToOcr(long maxFileSizeToOcr)

setMinFileSizeToOcr

@Field
public void setMinFileSizeToOcr(long minFileSizeToOcr)

setTimeout

@Field
public void setTimeout(int timeout)

setOutputType

@Field
public void setOutputType(String outputType)

setPreserveInterwordSpacing

@Field
public void setPreserveInterwordSpacing(boolean preserveInterwordSpacing)

setEnableImagePreprocessing

@Field
public void setEnableImagePreprocessing(boolean enableImagePreprocessing)

setDensity

@Field
public void setDensity(int density)

setDepth

@Field
public void setDepth(int depth)

setColorspace

@Field
public void setColorspace(String colorspace)

setFilter

@Field
public void setFilter(String filter)

setResize

@Field
public void setResize(int resize)

setApplyRotation

@Field
public void setApplyRotation(boolean applyRotation)

setPreloadLangs

@Field
public void setPreloadLangs(boolean preloadLangs)

If set to true and if tesseract is found, this will load the langs that result from --list-langs. At parse time, the parser will verify that tesseract has the requested lang available.

If set to false (the default) and tesseract is found, if a user requests a language that tesseract does not have data for, a TikaException will be thrown with tesseract's native exception message, which is a bit less readable.

Parameters:

preloadLangs -

getDefaultConfig

public TesseractOCRConfig getDefaultConfig()