com.qoppa.ocr

Class TessJNI

java.lang.Object

com.qoppa.ocr.TessJNI

public class TessJNI
extends Object

This class provides a native interface to the Tesseract OCR engine.

Author:

Qoppa Software

Constructor Summary

Constructors

Constructor and Description
TessJNI()

Method Summary

Modifier and Type	Method and Description
String	getOCRText(String language, PDFPage pdfPage, int dpi, OCROptions options) Performs OCR on a PDF page and returns a plain text result string.
String	getTesseractVersion() Returns the version of Tesseract that we're running.
String	performOCR(String language, BufferedImage image, int imageDPI) Deprecated. Use the version of this method that takes a pageNumber argument.
String	performOCR(String language, BufferedImage image, int imageDPI, int pageNumber) Performs OCR on an image and returns an hOCR result string.
String	performOCR(String language, PDFPage pdfPage, int dpi) Performs OCR on a PDF page and returns an hOCR result string.
String	performOCR(String language, PDFPage pdfPage, int dpi, OCROptions options) Performs OCR on a PDF page and returns an hOCR result string.
OCRPageResults	performOCRandOSD(String language, PDFPage pdfPage, int dpi, OCROptions options) Convert a PDF page to an image and run OCR on it, to return the OCR text in hOCR format, and page orientation information.

Methods inherited from class java.lang.Object

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

Constructor Detail

TessJNI

public TessJNI()

Method Detail

performOCR

public String performOCR(String language,
                         BufferedImage image,
                         int imageDPI,
                         int pageNumber)
                  throws OCRException

Performs OCR on an image and returns an hOCR result string. This method makes a call to the Tesseract OCR engine to perform character recognition on the image. The results are in hOCR format, a standard format for OCR results that includes recognized text as well as location and size information.

Parameters:

language - The language to use in performing the OCR. This can be multiple languages separated by a plus character (ex. "eng+fra")

image - The image to process

Returns:

The OCR results, in hOCR format.

Throws:

OCRException

performOCR

public String performOCR(String language,
                         BufferedImage image,
                         int imageDPI)
                  throws OCRException

Deprecated. Use the version of this method that takes a pageNumber argument.

Throws:

OCRException

performOCR

public String performOCR(String language,
                         PDFPage pdfPage,
                         int dpi)
                  throws PDFException,
                         OCRException

Performs OCR on a PDF page and returns an hOCR result string. This method converts the PDF page to an image and then makes a call to the Tesseract OCR engine to perform character recognition on the image. The results are in hOCR format, a standard format for OCR results that includes recognized text as well as location and size information.

Parameters:

language - The language to use in performing the OCR. This can be multiple languages separated a plus character (ex. "eng+fra").

pdfPage - The PDF page to process.

dpi - Dots per inch at which to render the image.

Returns:

The OCR results, in hOCR format.

Throws:

OCRException

PDFException

performOCR

public String performOCR(String language,
                         PDFPage pdfPage,
                         int dpi,
                         OCROptions options)
                  throws PDFException,
                         OCRException

Performs OCR on a PDF page and returns an hOCR result string. This method converts the PDF page to an image and then makes a call to the Tesseract OCR engine to perform character recognition on the image. The results are in hOCR format, a standard format for OCR results that includes recognized text as well as location and size information.

Parameters:

language - The language to use in performing the OCR. This can be multiple languages separated a plus character (ex. "eng+fra").

pdfPage - The PDF page to process.

dpi - Dots per inch at which to render the image.

options - The OCR options.

Returns:

The OCR results, in hOCR format.

Throws:

PDFException

OCRException

getOCRText

public String getOCRText(String language,
                         PDFPage pdfPage,
                         int dpi,
                         OCROptions options)
                  throws PDFException,
                         OCRException

Performs OCR on a PDF page and returns a plain text result string. This method converts the PDF page to an image and then makes a call to the Tesseract OCR engine to perform character recognition on the image. The results are in plain text.

Parameters:

language - The language to use in performing the OCR. This can be multiple languages separated a plus character (ex. "eng+fra").

pdfPage - The PDF page to process.

dpi - Dots per inch at which to render the image.

options - The OCR options.

Returns:

The OCR results, in plain text format.

Throws:

PDFException

OCRException

performOCRandOSD

public OCRPageResults performOCRandOSD(String language,
                                       PDFPage pdfPage,
                                       int dpi,
                                       OCROptions options)
                                throws PDFException,
                                       OCRException

Convert a PDF page to an image and run OCR on it, to return the OCR text in hOCR format, and page orientation information.

Parameters:

lang - Language to use when running OCR.

pdfPage - The PDF page to run OCR on.

dpi - The image resolution, in dots per inch

options - The options to use when running OCR.

Returns:

The results from running OCR on the page. Results include the text on the page in hOCR format as well as page orientation, line and writing direction.

Throws:

PDFException - For errors covnerting the PDF page to an image.

OCRException - For OCR errors.

getTesseractVersion

public String getTesseractVersion()

Returns the version of Tesseract that we're running.

Returns:

Tesseract version.