net.sourceforge.tess4j

Class Tesseract

java.lang.Object

net.sourceforge.tess4j.Tesseract

All Implemented Interfaces:

ITesseract

public class Tesseract
extends Object
implements ITesseract

An object layer on top of TessAPI, provides character recognition support for common image formats, and multi-page TIFF images beyond the uncompressed, binary TIFF format supported by Tesseract OCR engine. The extended capabilities are provided by the Java Advanced Imaging Image I/O Tools.

Support for PDF documents is available through Ghost4J, a JNA wrapper for GPL Ghostscript, which should be installed and included in system path.

Any program that uses the library will need to ensure that the required libraries (the .jar files for jna, jai-imageio, and ghost4j) are in its compile and run-time classpath.

Nested Class Summary

Nested classes/interfaces inherited from interface net.sourceforge.tess4j.ITesseract

ITesseract.RenderedFormat

Field Summary

Fields inherited from interface net.sourceforge.tess4j.ITesseract

htmlBeginTag, htmlEndTag

Constructor Summary

Constructors

Constructor and Description
Tesseract()

Method Summary

Modifier and Type	Method and Description
void	createDocuments(String[] filenames, String[] outputbases, List<ITesseract.RenderedFormat> formats) Creates documents.
void	createDocuments(String filename, String outputbase, List<ITesseract.RenderedFormat> formats) Creates documents for given renderer.
protected void	dispose() Releases all of the native resources used by this instance.
String	doOCR(BufferedImage bi) Performs OCR operation.
String	doOCR(BufferedImage bi, Rectangle rect) Performs OCR operation.
String	doOCR(File imageFile) Performs OCR operation.
String	doOCR(File imageFile, Rectangle rect) Performs OCR operation.
String	doOCR(int xsize, int ysize, ByteBuffer buf, Rectangle rect, int bpp) Performs OCR operation.
String	doOCR(int xsize, int ysize, ByteBuffer buf, String filename, Rectangle rect, int bpp) Performs OCR operation.
String	doOCR(List<IIOImage> imageList, Rectangle rect) Performs OCR operation.
String	doOCR(List<IIOImage> imageList, String filename, Rectangle rect) Performs OCR operation.
protected TessAPI	getAPI() Returns TessAPI object.
protected ITessAPI.TessBaseAPI	getHandle() Returns API handle.
static Tesseract	getInstance() Deprecated. As of Release 2.0, use default constructor instead.
protected String	getOCRText(String filename, int pageNum) Gets recognized text.
List<Rectangle>	getSegmentedRegions(BufferedImage bi, int pageIteratorLevel) Gets segmented regions at specified page iterator level.
List<Word>	getWords(BufferedImage bi, int pageIteratorLevel) Gets recognized words at specified page iterator level.
protected void	init() Initializes Tesseract engine.
void	setConfigs(List<String> configs) Sets configs to be passed to Tesseract's Init method.
void	setDatapath(String datapath) Sets path to tessdata.
void	setHocr(boolean hocr) Enables hocr output.
protected void	setImage(int xsize, int ysize, ByteBuffer buf, Rectangle rect, int bpp) Sets image to be processed.
protected void	setImage(RenderedImage image, Rectangle rect) A wrapper for setImage(int, int, ByteBuffer, Rectangle, int).
void	setLanguage(String language) Sets language for OCR.
void	setOcrEngineMode(int ocrEngineMode) Sets OCR engine mode.
void	setPageSegMode(int mode) Sets page segmentation mode.
void	setTessVariable(String key, String value) Set the value of Tesseract's internal parameter.
protected void	setTessVariables() Sets Tesseract's internal parameters.

Methods inherited from class java.lang.Object

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

Constructor Detail

Tesseract

public Tesseract()

Method Detail

getAPI

protected TessAPI getAPI()

Returns TessAPI object.

Returns:

api

getHandle

protected ITessAPI.TessBaseAPI getHandle()

Returns API handle.

Returns:

handle

getInstance

@Deprecated
public static Tesseract getInstance()

Deprecated. As of Release 2.0, use default constructor instead.

Gets an instance of the class library.

Returns:

instance

setDatapath

public void setDatapath(String datapath)

Sets path to tessdata.

Specified by:

setDatapath in interface ITesseract

Parameters:

datapath - the tessdata path to set

setLanguage

public void setLanguage(String language)

Sets language for OCR.

Specified by:

setLanguage in interface ITesseract

Parameters:

language - the language code, which follows ISO 639-3 standard.

setOcrEngineMode

public void setOcrEngineMode(int ocrEngineMode)

Sets OCR engine mode.

Specified by:

setOcrEngineMode in interface ITesseract

Parameters:

ocrEngineMode - the OcrEngineMode to set

setPageSegMode

public void setPageSegMode(int mode)

Sets page segmentation mode.

Specified by:

setPageSegMode in interface ITesseract

Parameters:

mode - the page segmentation mode to set

setHocr

public void setHocr(boolean hocr)

Enables hocr output.

Parameters:

hocr - to enable or disable hocr output

setTessVariable

public void setTessVariable(String key,
                            String value)

Set the value of Tesseract's internal parameter.

Specified by:

setTessVariable in interface ITesseract

Parameters:

key - variable name, e.g., tessedit_create_hocr, tessedit_char_whitelist, etc.

value - value for corresponding variable, e.g., "1", "0", "0123456789", etc.

setConfigs

public void setConfigs(List<String> configs)

Sets configs to be passed to Tesseract's Init method.

Specified by:

setConfigs in interface ITesseract

Parameters:

configs - list of config filenames, e.g., "digits", "bazaar", "quiet"

doOCR

public String doOCR(File imageFile)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

imageFile - an image file

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(File imageFile,
                    Rectangle rect)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

imageFile - an image file

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(BufferedImage bi)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

bi - a buffered image

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(BufferedImage bi,
                    Rectangle rect)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

bi - a buffered image

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(List<IIOImage> imageList,
                    Rectangle rect)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

imageList - a list of IIOImage objects

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(List<IIOImage> imageList,
                    String filename,
                    Rectangle rect)
             throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

imageList - a list of IIOImage objects

filename - input file name. Needed only for training and reading a UNLV zone file.

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(int xsize,
                    int ysize,
                    ByteBuffer buf,
                    Rectangle rect,
                    int bpp)
             throws TesseractException

Performs OCR operation. Use SetImage, (optionally) SetRectangle, and one or more of the Get*Text functions.

Specified by:

doOCR in interface ITesseract

Parameters:

xsize - width of image

ysize - height of image

buf - pixel data

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

bpp - bits per pixel, represents the bit depth of the image, with 1 for binary bitmap, 8 for gray, and 24 for color RGB.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public String doOCR(int xsize,
                    int ysize,
                    ByteBuffer buf,
                    String filename,
                    Rectangle rect,
                    int bpp)
             throws TesseractException

Performs OCR operation. Use SetImage, (optionally) SetRectangle, and one or more of the Get*Text functions.

Specified by:

doOCR in interface ITesseract

Parameters:

xsize - width of image

ysize - height of image

buf - pixel data

filename - input file name. Needed only for training and reading a UNLV zone file.

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

bpp - bits per pixel, represents the bit depth of the image, with 1 for binary bitmap, 8 for gray, and 24 for color RGB.

Returns:

the recognized text

Throws:

TesseractException

init

protected void init()

Initializes Tesseract engine.

setTessVariables

protected void setTessVariables()

Sets Tesseract's internal parameters.

setImage

protected void setImage(RenderedImage image,
                        Rectangle rect)
                 throws IOException

A wrapper for setImage(int, int, ByteBuffer, Rectangle, int).

Parameters:

image - a rendered image

rect - region of interest

Throws:

IOException

setImage

protected void setImage(int xsize,
                        int ysize,
                        ByteBuffer buf,
                        Rectangle rect,
                        int bpp)

Sets image to be processed.

Parameters:

xsize - width of image

ysize - height of image

buf - pixel data

rect - the bounding rectangle defines the region of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

bpp - bits per pixel, represents the bit depth of the image, with 1 for binary bitmap, 8 for gray, and 24 for color RGB.

getOCRText

protected String getOCRText(String filename,
                            int pageNum)

Gets recognized text.

Parameters:

filename - input file name. Needed only for reading a UNLV zone file.

pageNum - page number; needed for hocr paging.

Returns:

the recognized text

createDocuments

public void createDocuments(String filename,
                            String outputbase,
                            List<ITesseract.RenderedFormat> formats)
                     throws TesseractException

Creates documents for given renderer.

Specified by:

createDocuments in interface ITesseract

Parameters:

filename - input image

outputbase - output filename without extension

formats - types of renderer

Throws:

TesseractException

createDocuments

public void createDocuments(String[] filenames,
                            String[] outputbases,
                            List<ITesseract.RenderedFormat> formats)
                     throws TesseractException

Creates documents.

Specified by:

createDocuments in interface ITesseract

Parameters:

filenames - array of input files

outputbases - array of output filenames without extension

formats - types of renderer

Throws:

TesseractException

getSegmentedRegions

public List<Rectangle> getSegmentedRegions(BufferedImage bi,
                                           int pageIteratorLevel)
                                    throws TesseractException

Gets segmented regions at specified page iterator level.

Specified by:

getSegmentedRegions in interface ITesseract

Parameters:

bi - input image

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of Rectangle

Throws:

TesseractException

getWords

public List<Word> getWords(BufferedImage bi,
                           int pageIteratorLevel)

Gets recognized words at specified page iterator level.

Specified by:

getWords in interface ITesseract

Parameters:

bi - input image

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of Word

dispose

protected void dispose()

Releases all of the native resources used by this instance.