Class JBIG2ImageReader

java.lang.Object

javax.imageio.ImageReader

org.apache.pdfbox.jbig2.JBIG2ImageReader

public class JBIG2ImageReader
extends ImageReader

See Also:

• ImageReader

Field Summary

Fields

Modifier and Type	Field	Description
private JBIG2Document	document	JBIG2 document to which we delegate current work.
private JBIG2Globals	globals	Globals are JBIG2 segments for PDF wide use.

Fields inherited from class ImageReader

availableLocales, ignoreMetadata, input, locale, minIndex, originatingProvider, progressListeners, seekForwardOnly, updateListeners, warningListeners, warningLocales

Constructor Summary

Constructors

Constructor	Description
JBIG2ImageReader(ImageReaderSpi originatingProvider)

Method Summary

Modifier and Type	Method	Description
boolean	canReadRaster()
JBIG2ReadParam	getDefaultReadParam()
private JBIG2ReadParam	getDefaultReadParam(int imageIndex)	Returns a default ImageReadParam object for a specific page.
private JBIG2Document	getDocument()
JBIG2Globals	getGlobals()	Returns decoded segments that has been set as globals.
int	getHeight(int imageIndex)	Calculates the height of the specified page.
IIOMetadata	getImageMetadata(int imageIndex)	Simply returns the JBIG2ImageMetadata.
Iterator<ImageTypeSpecifier>	getImageTypes(int imageIndex)	Returns the iterator for available image types.
int	getNumImages(boolean allowSearch)
private JBIG2Page	getPage(int imageIndex)
IIOMetadata	getStreamMetadata()	This ImageIO plugin doesn't record IIOMetadata.
int	getWidth(int imageIndex)	Calculates the width of the specified page.
JBIG2Globals	processGlobals(ImageInputStream globalsInputStream)	Decodes and returns the global segments.
BufferedImage	read(int imageIndex, ImageReadParam param)	Returns the decoded image of specified page considering the given JBIG2ReadParams.
Raster	readRaster(int imageIndex, ImageReadParam param)
void	setGlobals(JBIG2Globals globals)	Simply sets the globals.
void	setInput(Object input, boolean seekForwardOnly, boolean ignoreMetadata)

Methods inherited from class ImageReader

abort, abortRequested, addIIOReadProgressListener, addIIOReadUpdateListener, addIIOReadWarningListener, checkReadParamBandSettings, clearAbortRequest, computeRegions, dispose, getAspectRatio, getAvailableLocales, getDestination, getFormatName, getImageMetadata, getInput, getLocale, getMinIndex, getNumThumbnails, getOriginatingProvider, getRawImageType, getSourceRegion, getStreamMetadata, getThumbnailHeight, getThumbnailWidth, getTileGridXOffset, getTileGridYOffset, getTileHeight, getTileWidth, hasThumbnails, isIgnoringMetadata, isImageTiled, isRandomAccessEasy, isSeekForwardOnly, processImageComplete, processImageProgress, processImageStarted, processImageUpdate, processPassComplete, processPassStarted, processReadAborted, processSequenceComplete, processSequenceStarted, processThumbnailComplete, processThumbnailPassComplete, processThumbnailPassStarted, processThumbnailProgress, processThumbnailStarted, processThumbnailUpdate, processWarningOccurred, processWarningOccurred, read, readAll, readAll, readAsRenderedImage, readerSupportsThumbnails, readThumbnail, readTile, readTileRaster, removeAllIIOReadProgressListeners, removeAllIIOReadUpdateListeners, removeAllIIOReadWarningListeners, removeIIOReadProgressListener, removeIIOReadUpdateListener, removeIIOReadWarningListener, reset, setInput, setInput, setLocale

Methods inherited from class Object

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

Field Details

document

private JBIG2Document document

JBIG2 document to which we delegate current work.

globals

private JBIG2Globals globals

Globals are JBIG2 segments for PDF wide use.

Constructor Details

JBIG2ImageReader

public JBIG2ImageReader(ImageReaderSpi originatingProvider)
                 throws IOException

Parameters:

originatingProvider - - The ImageReaderSpi that is invoking this constructor, or null.

Throws:

IOException - if something went wrong while reading the provided stream.

See Also:

• ImageReader(ImageReaderSpi)

Method Details

getDefaultReadParam

public JBIG2ReadParam getDefaultReadParam()

Overrides:

getDefaultReadParam in class ImageReader

See Also:

• ImageReader.getDefaultReadParam()

getDefaultReadParam

private JBIG2ReadParam getDefaultReadParam(int imageIndex)

Returns a default ImageReadParam object for a specific page.

Parameters:

imageIndex - - The page number.

Returns:

getWidth

public int getWidth(int imageIndex)
             throws IOException

Calculates the width of the specified page.

Specified by:

getWidth in class ImageReader

Parameters:

imageIndex - - The image index. In this case it is the page number.

Returns:

The width of the specified page.

Throws:

IOException - if an error occurs reading the width information from the input source.

getHeight

public int getHeight(int imageIndex)
              throws IOException

Calculates the height of the specified page.

Specified by:

getHeight in class ImageReader

Parameters:

imageIndex - - The image index. In this case it is the page number.

Returns:

The height of the specified page or 0 if an error occurred.

Throws:

IOException - if an error occurs reading the height information from the input source.

getImageMetadata

public IIOMetadata getImageMetadata(int imageIndex)
                             throws IOException

Simply returns the JBIG2ImageMetadata.

Specified by:

getImageMetadata in class ImageReader

Returns:

The associated JBIG2ImageMetadata.

Throws:

IOException - if an error occurs reading the height information from the input source.

getImageTypes

public Iterator<ImageTypeSpecifier> getImageTypes(int imageIndex)
                                           throws IOException

Returns the iterator for available image types.

Specified by:

getImageTypes in class ImageReader

Parameters:

imageIndex - - The page number.

Returns:

An Iterator for available image types.

Throws:

IOException - if an error occurs reading the height information from the input source.

getNumImages

public int getNumImages(boolean allowSearch)
                 throws IOException

Specified by:

getNumImages in class ImageReader

Throws:

IOException

See Also:

• ImageReader.getNumImages(boolean)

getStreamMetadata

public IIOMetadata getStreamMetadata()

This ImageIO plugin doesn't record IIOMetadata.

Specified by:

getStreamMetadata in class ImageReader

Returns:

null at every call.

getGlobals

public JBIG2Globals getGlobals()
                        throws IOException

Returns decoded segments that has been set as globals. Globals are jbig2 segments that are used in embedded case for file wide access. They are not assigned to a specific page.

Returns:

Decoded global segments.

Throws:

IOException - if an error occurs reading the height information from the input source.

read

public BufferedImage read(int imageIndex,
 ImageReadParam param)
                   throws IOException

Returns the decoded image of specified page considering the given JBIG2ReadParams.

Specified by:

read in class ImageReader

Throws:

IOException

See Also:

• ImageReader.read(int, ImageReadParam)

canReadRaster

public boolean canReadRaster()

Overrides:

canReadRaster in class ImageReader

readRaster

public Raster readRaster(int imageIndex,
 ImageReadParam param)
                  throws IOException

Overrides:

readRaster in class ImageReader

Throws:

IOException

processGlobals

public JBIG2Globals processGlobals(ImageInputStream globalsInputStream)
                            throws IOException

Decodes and returns the global segments.

Parameters:

globalsInputStream - - The input stream of globals data.

Returns:

The decoded JBIG2Globals.

Throws:

IOException - if an error occurs reading the height information from the input source.

setGlobals

public void setGlobals(JBIG2Globals globals)
                throws IOException

Simply sets the globals.

Parameters:

globals - - The globals to set.

Throws:

IOException - if an error occurs

setInput

public void setInput(Object input,
 boolean seekForwardOnly,
 boolean ignoreMetadata)

Overrides:

setInput in class ImageReader

See Also:

• ImageReader.setInput(Object, boolean, boolean)

getDocument

private JBIG2Document getDocument()
                           throws IOException

Throws:

IOException

getPage

private JBIG2Page getPage(int imageIndex)
                   throws IOException

Throws:

IOException