net.sourceforge.tess4j

Class Tesseract

java.lang.Object

net.sourceforge.tess4j.Tesseract

All Implemented Interfaces:

ITesseract

public class Tesseract
extends java.lang.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 PDFBox.

Any program that uses the library will need to ensure that the required libraries (the .jar files for jna and jai-imageio) 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

DOCUMENT_TITLE, htmlBeginTag, htmlEndTag, PAGE_SEPARATOR

Constructor Summary

Constructors

Constructor and Description
Tesseract()

Method Summary

Modifier and Type	Method and Description
void	createDocuments(java.lang.String[] filenames, java.lang.String[] outputbases, java.util.List<ITesseract.RenderedFormat> formats) Creates documents for given renderer.
java.util.List<OCRResult>	createDocumentsWithResults(java.awt.image.BufferedImage[] bis, java.lang.String[] filenames, java.lang.String[] outputbases, java.util.List<ITesseract.RenderedFormat> formats, int pageIteratorLevel) Creates documents with OCR results for given renderers at specified page iterator level.
OCRResult	createDocumentsWithResults(java.awt.image.BufferedImage bi, java.lang.String filename, java.lang.String outputbase, java.util.List<ITesseract.RenderedFormat> formats, int pageIteratorLevel) Creates documents with OCR result for given renderers at specified page iterator level.
java.util.List<OCRResult>	createDocumentsWithResults(java.lang.String[] filenames, java.lang.String[] outputbases, java.util.List<ITesseract.RenderedFormat> formats, int pageIteratorLevel) Creates documents with OCR results for given renderers at specified page iterator level.
OCRResult	createDocumentsWithResults(java.lang.String filename, java.lang.String outputbase, java.util.List<ITesseract.RenderedFormat> formats, int pageIteratorLevel) Creates documents with OCR result for given renderers at specified page iterator level.
protected void	dispose() Releases all of the native resources used by this instance.
java.lang.String	doOCR(java.io.File inputFile, java.util.List<java.awt.Rectangle> rects) Performs OCR operation.
java.lang.String	doOCR(int xsize, int ysize, java.nio.ByteBuffer buf, int bpp, java.lang.String filename, java.util.List<java.awt.Rectangle> rects) Performs OCR operation.
java.lang.String	doOCR(java.util.List<javax.imageio.IIOImage> imageList, java.lang.String filename, java.util.List<java.util.List<java.awt.Rectangle>> roiss) Performs OCR operation.
protected TessAPI	getAPI() Returns TessAPI object.
protected ITessAPI.TessBaseAPI	getHandle() Returns API handle.
protected java.lang.String	getOCRText(java.lang.String filename, int pageNum) Gets recognized text.
OSDResult	getOSD(java.awt.image.BufferedImage bi) Gets the detected orientation of the input image and apparent script (alphabet).
OSDResult	getOSD(java.io.File imageFile) Gets the detected orientation of the input image and apparent script (alphabet).
java.util.List<java.awt.Rectangle>	getSegmentedRegions(java.awt.image.BufferedImage bi, int pageIteratorLevel) Gets segmented regions at specified page iterator level.
java.util.List<Word>	getWords(java.util.List<java.awt.image.BufferedImage> biList, int pageIteratorLevel) Gets recognized words at specified page iterator level.
protected void	init() Initializes Tesseract engine.
void	setConfigs(java.util.List<java.lang.String> configs) Sets configs to be passed to Tesseract's Init method.
void	setDatapath(java.lang.String datapath) Sets path to tessdata.
protected void	setImage(int xsize, int ysize, java.nio.ByteBuffer buf, int bpp) Sets image to be processed.
protected void	setImage(java.awt.image.RenderedImage image) Sets image to be processed.
void	setLanguage(java.lang.String language) Sets language for OCR.
void	setOcrEngineMode(int ocrEngineMode) Sets OCR engine mode.
void	setPageSegMode(int mode) Sets page segmentation mode.
protected void	setROI(java.awt.Rectangle rect) Sets region of interest.
void	setVariable(java.lang.String key, java.lang.String value) Set the value of Tesseract's internal parameter.
protected void	setVariables() Sets Tesseract's internal parameters.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sourceforge.tess4j.ITesseract

createDocuments, doOCR, doOCR, doOCR, getWords

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

setDatapath

public void setDatapath(java.lang.String datapath)

Sets path to tessdata.

Specified by:

setDatapath in interface ITesseract

Parameters:

datapath - the tessdata path to set

setLanguage

public void setLanguage(java.lang.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

setVariable

public void setVariable(java.lang.String key,
                        java.lang.String value)

Set the value of Tesseract's internal parameter.

Specified by:

setVariable 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(java.util.List<java.lang.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 java.lang.String doOCR(java.io.File inputFile,
                              java.util.List<java.awt.Rectangle> rects)
                       throws TesseractException

Performs OCR operation.

Specified by:

doOCR in interface ITesseract

Parameters:

inputFile - an image file

rects - list of the bounding rectangles defines the regions 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 java.lang.String doOCR(java.util.List<javax.imageio.IIOImage> imageList,
                              java.lang.String filename,
                              java.util.List<java.util.List<java.awt.Rectangle>> roiss)
                       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.

roiss - list of list of the bounding rectangles defines the regions of the images to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

doOCR

public java.lang.String doOCR(int xsize,
                              int ysize,
                              java.nio.ByteBuffer buf,
                              int bpp,
                              java.lang.String filename,
                              java.util.List<java.awt.Rectangle> rects)
                       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

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

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

rects - list of the bounding rectangle defines the regions of the image to be recognized. A rectangle of zero dimension or null indicates the whole image.

Returns:

the recognized text

Throws:

TesseractException

init

protected void init()

Initializes Tesseract engine.

setVariables

protected void setVariables()

Sets Tesseract's internal parameters.

setImage

protected void setImage(java.awt.image.RenderedImage image)
                 throws java.io.IOException

Sets image to be processed.
Pix vs raw, which to use? Pix is the preferred input for efficiency, since raw buffers are copied.
SetImage for Pix clones its input, so the source pix may be pixDestroyed immediately after, but may not go away until after the Thresholder has finished with it.

Parameters:

image - a rendered image

Throws:

java.io.IOException

setImage

protected void setImage(int xsize,
                        int ysize,
                        java.nio.ByteBuffer buf,
                        int bpp)

Sets image to be processed.
Greyscale of 8 and color of 24 or 32 bits per pixel may be given. Palette color images will not work properly and must be converted to 24 bit.
Binary images of 1 bit per pixel may also be given but they must be byte packed with the MSB of the first byte being the first pixel, and a one pixel is WHITE.

Parameters:

xsize - width of image

ysize - height of image

buf - pixel data

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

setROI

protected void setROI(java.awt.Rectangle rect)

Sets region of interest.

Parameters:

rect - region of interest

getOCRText

protected java.lang.String getOCRText(java.lang.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(java.lang.String[] filenames,
                            java.lang.String[] outputbases,
                            java.util.List<ITesseract.RenderedFormat> formats)
                     throws TesseractException

Creates documents for given renderer.

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 java.util.List<java.awt.Rectangle> getSegmentedRegions(java.awt.image.BufferedImage bi,
                                                              int pageIteratorLevel)
                                                       throws TesseractException

Gets segmented regions at specified page iterator level.

Specified by:

getSegmentedRegions in interface ITesseract

Parameters:

bi - input buffered image

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of Rectangle

Throws:

TesseractException

getWords

public java.util.List<Word> getWords(java.util.List<java.awt.image.BufferedImage> biList,
                                     int pageIteratorLevel)

Gets recognized words at specified page iterator level.

Specified by:

getWords in interface ITesseract

Parameters:

biList - list of input buffered images

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of Word

createDocumentsWithResults

public OCRResult createDocumentsWithResults(java.awt.image.BufferedImage bi,
                                            java.lang.String filename,
                                            java.lang.String outputbase,
                                            java.util.List<ITesseract.RenderedFormat> formats,
                                            int pageIteratorLevel)
                                     throws TesseractException

Creates documents with OCR result for given renderers at specified page iterator level.

Specified by:

createDocumentsWithResults in interface ITesseract

Parameters:

bi - input buffered image

filename - filename (optional)

outputbase - output filenames without extension

formats - types of renderer

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

OCR result

Throws:

TesseractException

createDocumentsWithResults

public java.util.List<OCRResult> createDocumentsWithResults(java.awt.image.BufferedImage[] bis,
                                                            java.lang.String[] filenames,
                                                            java.lang.String[] outputbases,
                                                            java.util.List<ITesseract.RenderedFormat> formats,
                                                            int pageIteratorLevel)
                                                     throws TesseractException

Creates documents with OCR results for given renderers at specified page iterator level.

Specified by:

createDocumentsWithResults in interface ITesseract

Parameters:

bis - array of input buffered images

filenames - array of filenames

outputbases - array of output filenames without extension

formats - types of renderer

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of OCR results

Throws:

TesseractException

createDocumentsWithResults

public OCRResult createDocumentsWithResults(java.lang.String filename,
                                            java.lang.String outputbase,
                                            java.util.List<ITesseract.RenderedFormat> formats,
                                            int pageIteratorLevel)
                                     throws TesseractException

Creates documents with OCR result for given renderers at specified page iterator level.

Specified by:

createDocumentsWithResults in interface ITesseract

Parameters:

filename - input file

outputbase - output filenames without extension

formats - types of renderer

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

OCR result

Throws:

TesseractException

createDocumentsWithResults

public java.util.List<OCRResult> createDocumentsWithResults(java.lang.String[] filenames,
                                                            java.lang.String[] outputbases,
                                                            java.util.List<ITesseract.RenderedFormat> formats,
                                                            int pageIteratorLevel)
                                                     throws TesseractException

Creates documents with OCR results for given renderers at specified page iterator level.

Specified by:

createDocumentsWithResults in interface ITesseract

Parameters:

filenames - array of input files

outputbases - array of output filenames without extension

formats - types of renderer

pageIteratorLevel - TessPageIteratorLevel enum

Returns:

list of OCR results

Throws:

TesseractException

getOSD

public OSDResult getOSD(java.io.File imageFile)

Gets the detected orientation of the input image and apparent script (alphabet).

Specified by:

getOSD in interface ITesseract

Parameters:

imageFile - an image file

Returns:

image orientation and script name

getOSD

public OSDResult getOSD(java.awt.image.BufferedImage bi)

Gets the detected orientation of the input image and apparent script (alphabet).

Specified by:

getOSD in interface ITesseract

Parameters:

bi - a buffered image

Returns:

image orientation and script name

dispose

protected void dispose()

Releases all of the native resources used by this instance.