Package org.apache.pdfbox.jbig2.segments

Class HalftoneRegion

java.lang.Object

org.apache.pdfbox.jbig2.segments.HalftoneRegion

All Implemented Interfaces:

Region, SegmentData

public class HalftoneRegion
extends java.lang.Object
implements Region

This class represents the data of segment type "Halftone region". Parsing is described in 7.4.5, page 67. Decoding procedure in 6.6.5 and 7.4.5.2.

Field Summary

Fields

Modifier and Type	Field	Description
private long	dataHeaderLength
private long	dataHeaderOffset
private long	dataLength
private long	dataOffset
private Bitmap	halftoneRegionBitmap	Decoded data
private CombinationOperator	hCombinationOperator
private byte	hDefaultPixel	Halftone segment information field, 7.4.5.1.1
private int	hGridHeight	Height of the gray-scale image, 7.4.5.1.2.2
private int	hGridWidth	Width of the gray-scale image, 7.4.5.1.2.1
private int	hGridX	Horizontal offset of the grid, 7.4.5.1.2.3
private int	hGridY	Vertical offset of the grid, 7.4.5.1.2.4
private int	hRegionX	Horizontal coordinate of the halftone grid vector, 7.4.5.1.3.1
private int	hRegionY	Vertical coordinate of the halftone grod vector, 7.4.5.1.3.2
private boolean	hSkipEnabled
private byte	hTemplate
private boolean	isMMREncoded
private java.util.ArrayList<Bitmap>	patterns	Previously decoded data from other regions or dictionaries, stored to use as patterns in this region.
private RegionSegmentInformation	regionInfo	Region segment information field, 7.4.1
private SegmentHeader	segmentHeader
private SubInputStream	subInputStream

Constructor Summary

Constructors

Constructor	Description
HalftoneRegion()
HalftoneRegion(SubInputStream subInputStream)
HalftoneRegion(SubInputStream subInputStream, SegmentHeader segmentHeader)

Method Summary

Modifier and Type	Method	Description
private Bitmap[]	combineGrayScalePlanes(Bitmap[] grayScalePlanes, int j)
private int[][]	computeGrayScaleValues(Bitmap[] grayScalePlanes, int bitsPerValue)
private void	computeSegmentDataStructure()
private int	computeX(int m, int n)
private int	computeY(int m, int n)
CombinationOperator	getCombinationOperator()
protected byte	getHDefaultPixel()
protected int	getHGridHeight()
protected int	getHGridWidth()
protected int	getHGridX()
protected int	getHGridY()
protected int	getHRegionX()
protected int	getHRegionY()
protected byte	getHTemplate()
private java.util.ArrayList<Bitmap>	getPatterns()
Bitmap	getRegionBitmap()	The procedure is described in JBIG2 ISO standard, 6.6.5.
RegionSegmentInformation	getRegionInfo()	Simply returns the RegionSegmentInformation.
private int[][]	grayScaleDecoding(int bitsPerValue)	Gray-scale image decoding procedure is special for halftone region decoding and is described in Annex C.5 on page 98.
void	init(SegmentHeader header, SubInputStream sis)	Parse the stream and read information of header.
protected boolean	isHSkipEnabled()
protected boolean	isMMREncoded()
private void	parseHeader()
private void	renderPattern(int[][] grayScaleValues)	This method draws the pattern into the region bitmap (htReg), as described in 6.6.5.2, page 42
private int	shiftAndFill(int value)

Methods inherited from class java.lang.Object

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

Field Detail

subInputStream

private SubInputStream subInputStream

segmentHeader

private SegmentHeader segmentHeader

dataHeaderOffset

private long dataHeaderOffset

dataHeaderLength

private long dataHeaderLength

dataOffset

private long dataOffset

dataLength

private long dataLength

regionInfo

private RegionSegmentInformation regionInfo

Region segment information field, 7.4.1

hDefaultPixel

private byte hDefaultPixel

Halftone segment information field, 7.4.5.1.1

hCombinationOperator

private CombinationOperator hCombinationOperator

hSkipEnabled

private boolean hSkipEnabled

hTemplate

private byte hTemplate

isMMREncoded

private boolean isMMREncoded

hGridWidth

private int hGridWidth

Width of the gray-scale image, 7.4.5.1.2.1

hGridHeight

private int hGridHeight

Height of the gray-scale image, 7.4.5.1.2.2

hGridX

private int hGridX

Horizontal offset of the grid, 7.4.5.1.2.3

hGridY

private int hGridY

Vertical offset of the grid, 7.4.5.1.2.4

hRegionX

private int hRegionX

Horizontal coordinate of the halftone grid vector, 7.4.5.1.3.1

hRegionY

private int hRegionY

Vertical coordinate of the halftone grod vector, 7.4.5.1.3.2

halftoneRegionBitmap

private Bitmap halftoneRegionBitmap

Decoded data

patterns

private java.util.ArrayList<Bitmap> patterns

Previously decoded data from other regions or dictionaries, stored to use as patterns in this region.

Constructor Detail

HalftoneRegion

public HalftoneRegion()

HalftoneRegion

public HalftoneRegion(SubInputStream subInputStream)

HalftoneRegion

public HalftoneRegion(SubInputStream subInputStream,
                      SegmentHeader segmentHeader)

Method Detail

parseHeader

private void parseHeader()
                  throws java.io.IOException,
                         InvalidHeaderValueException

Throws:

java.io.IOException

InvalidHeaderValueException

computeSegmentDataStructure

private void computeSegmentDataStructure()
                                  throws java.io.IOException

Throws:

java.io.IOException

getRegionBitmap

public Bitmap getRegionBitmap()
                       throws java.io.IOException,
                              InvalidHeaderValueException

The procedure is described in JBIG2 ISO standard, 6.6.5.

Specified by:

getRegionBitmap in interface Region

Returns:

The decoded Bitmap of this region.

Throws:

java.io.IOException - if an underlying IO operation fails

InvalidHeaderValueException - if a segment header value is invalid

renderPattern

private void renderPattern(int[][] grayScaleValues)

This method draws the pattern into the region bitmap (htReg), as described in 6.6.5.2, page 42

getPatterns

private java.util.ArrayList<Bitmap> getPatterns()
                                         throws InvalidHeaderValueException,
                                                java.io.IOException

Throws:

java.io.IOException

InvalidHeaderValueException

grayScaleDecoding

private int[][] grayScaleDecoding(int bitsPerValue)
                           throws java.io.IOException

Gray-scale image decoding procedure is special for halftone region decoding and is described in Annex C.5 on page 98.

Throws:

java.io.IOException

combineGrayScalePlanes

private Bitmap[] combineGrayScalePlanes(Bitmap[] grayScalePlanes,
                                        int j)

computeGrayScaleValues

private int[][] computeGrayScaleValues(Bitmap[] grayScalePlanes,
                                       int bitsPerValue)

computeX

private int computeX(int m,
                     int n)

computeY

private int computeY(int m,
                     int n)

shiftAndFill

private int shiftAndFill(int value)

init

public void init(SegmentHeader header,
                 SubInputStream sis)
          throws InvalidHeaderValueException,
                 java.io.IOException

Description copied from interface: SegmentData

Parse the stream and read information of header.

Specified by:

init in interface SegmentData

Parameters:

header - - The segments' header (to make referred-to segments available in data part).

sis - - Wrapped ImageInputStream into SubInputStream.

Throws:

InvalidHeaderValueException - if the segment header value is invalid

java.io.IOException - if an underlying IO operation fails

getCombinationOperator

public CombinationOperator getCombinationOperator()

getRegionInfo

public RegionSegmentInformation getRegionInfo()

Description copied from interface: Region

Simply returns the RegionSegmentInformation.

Specified by:

getRegionInfo in interface Region

Returns:

The RegionSegmentInformation.

getHTemplate

protected byte getHTemplate()

isHSkipEnabled

protected boolean isHSkipEnabled()

isMMREncoded

protected boolean isMMREncoded()

getHGridWidth

protected int getHGridWidth()

getHGridHeight

protected int getHGridHeight()

getHGridX

protected int getHGridX()

getHGridY

protected int getHGridY()

getHRegionX

protected int getHRegionX()

getHRegionY

protected int getHRegionY()

getHDefaultPixel

protected byte getHDefaultPixel()