Package net.sourceforge.lept4j.util

Class LeptUtils

java.lang.Object

net.sourceforge.lept4j.util.LeptUtils

public class LeptUtils
extends Object

Various utility methods for Leptonica.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final float	deg2rad
(package private) static final String	JAI_IMAGE_WRITER_MESSAGE
static final String	SEL_STR2	HMT (with just misses) for speckle up to 2x2
static final String	SEL_STR3	HMT (with just misses) for speckle up to 3x3
(package private) static final String	TIFF_FORMAT

Constructor Summary

Constructors

Constructor	Description
LeptUtils()

Method Summary

Modifier and Type	Method	Description
static Pix	convertImageToPix(BufferedImage image)	Deprecated.
static Pix	convertImageToPix(RenderedImage image)	Converts RenderedImage to Leptonica Pix .
static BufferedImage	convertPixToImage(Pix pix)	Converts Leptonica Pix to BufferedImage.
static Pix	despeckle(Pix pixs, String selStr, int selSize)	Reduces speckle noise in image.
static void	dispose(com.sun.jna.Structure resource)	Disposes of Leptonica native resource.
static void	disposePix(Pix pix)	Disposes of Pix resource.
static ByteBuffer	getImageByteBuffer(RenderedImage image)	Gets image data of a RenderedImage object.
static String	removeLines(String imageFile)	Remove lines from image file.
static Pix	removeLines(Pix pixs)	Removes horizontal lines from a grayscale image.

Methods inherited from class java.lang.Object

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

Field Details

JAI_IMAGE_WRITER_MESSAGE

static final String JAI_IMAGE_WRITER_MESSAGE

See Also:

• Constant Field Values

TIFF_FORMAT

static final String TIFF_FORMAT

See Also:

• Constant Field Values

deg2rad

static final float deg2rad

See Also:

• Constant Field Values

SEL_STR2

public static final String SEL_STR2

HMT (with just misses) for speckle up to 2x2

"oooo"
"oC o"
"o  o"
"oooo"

See Also:

• Constant Field Values

SEL_STR3

public static final String SEL_STR3

HMT (with just misses) for speckle up to 3x3

"ooooo"
"oC  o"
"o   o"
"o   o"
"ooooo"

See Also:

• Constant Field Values

Constructor Details

LeptUtils

public LeptUtils()

Method Details

convertPixToImage

public static BufferedImage convertPixToImage(Pix pix)
                                       throws IOException

Converts Leptonica Pix to BufferedImage.

Parameters:

pix - source pix

Returns:

BufferedImage output image

Throws:

IOException

convertImageToPix

@Deprecated
public static Pix convertImageToPix(BufferedImage image)
                             throws IOException

Deprecated.

Converts BufferedImage to Leptonica Pix .

Parameters:

image - source image

Returns:

Pix output pix

Throws:

IOException

convertImageToPix

public static Pix convertImageToPix(RenderedImage image)
                             throws IOException

Converts RenderedImage to Leptonica Pix .

Parameters:

image - source image

Returns:

Pix output pix

Throws:

IOException

getImageByteBuffer

public static ByteBuffer getImageByteBuffer(RenderedImage image)
                                     throws IOException

Gets image data of a RenderedImage object.

Parameters:

image - a RenderedImage object

Returns:

a byte buffer of image data

Throws:

IOException

removeLines

public static Pix removeLines(Pix pixs)

Removes horizontal lines from a grayscale image. The algorithm is based on Leptonica lineremoval.c example.
To remove vertical lines, rotate the image 90 degrees first, remove the horizontal lines, and rotate it back.

Parameters:

pixs - input pix

Returns:

pix with lines removed

See Also:

• line-removal

removeLines

public static String removeLines(String imageFile)
                          throws IOException

Remove lines from image file.

Parameters:

imageFile - input image

Returns:

temporary multi-page TIFF image file

Throws:

IOException

despeckle

public static Pix despeckle(Pix pixs,
 String selStr,
 int selSize)

Reduces speckle noise in image. The algorithm is based on Leptonica speckle_reg.c example demonstrating morphological method of removing speckle.

Parameters:

pixs - input pix

selStr - hit-miss sels in 2D layout; SEL_STR2 and SEL_STR3 are predefined values

selSize - 2 for 2x2, 3 for 3x3

Returns:

pix with speckle removed

disposePix

public static void disposePix(Pix pix)

Disposes of Pix resource.

Parameters:

pix -

dispose

public static void dispose(com.sun.jna.Structure resource)

Disposes of Leptonica native resource.

Parameters:

resource - A Leptonica object, such as Pix, Pixa, Box, Boxa, PixColormap, etc.