Apache PDFBox 3.0.4 · org.apache.pdfbox.jbig2.JBIG2ImageReader

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

Access	Constructor and Description
public	JBIG2ImageReader(ImageReaderSpi - The `ImageReaderSpi` that is invoking this constructor, or `null`. originatingProvider)

Method Summary

Modifier and Type	Method and Description
public boolean	canReadRaster() Overrides javax.imageio.ImageReader.canReadRaster. Returns `true` if this plug-in supports reading just a `Raster` of pixel data.
public JBIG2ReadParam	getDefaultReadParam() Overrides javax.imageio.ImageReader.getDefaultReadParam. Returns a default `ImageReadParam` object appropriate for this format.
private JBIG2ReadParam	getDefaultReadParam(final int - The page number. imageIndex) Returns a default ImageReadParam object for a specific page.
private JBIG2Document	getDocument()
public JBIG2Globals	Returns: Decoded global segments. getGlobals() Returns decoded segments that has been set as globals.
public int	Returns: The height of the specified page or `0` if an error occurred. getHeight(int - The image index. In this case it is the page number. imageIndex) Implements abstract javax.imageio.ImageReader.getHeight. Calculates the height of the specified page.
public IIOMetadata	Returns: The associated `JBIG2ImageMetadata`. getImageMetadata(int the index of the image whose metadata is to be retrieved. imageIndex) Implements abstract javax.imageio.ImageReader.getImageMetadata. Simply returns the `JBIG2ImageMetadata`.
public Iterator<ImageTypeSpecifier>	Returns: An `Iterator` for available image types. getImageTypes(int - The page number. imageIndex) Implements abstract javax.imageio.ImageReader.getImageTypes. Returns the iterator for available image types.
public int	getNumImages(boolean if `true`, the true number of images will be returned even if a search is required. If `false`, the reader may return `-1` without performing the search. allowSearch) Implements abstract javax.imageio.ImageReader.getNumImages. Returns the number of images, not including thumbnails, available from the current input source.
private JBIG2Page	getPage(int imageIndex)
public IIOMetadata	Returns: `null` at every call. getStreamMetadata() Implements abstract javax.imageio.ImageReader.getStreamMetadata. This ImageIO plugin doesn't record `IIOMetadata`.
public int	Returns: The width of the specified page. getWidth(int - The image index. In this case it is the page number. imageIndex) Implements abstract javax.imageio.ImageReader.getWidth. Calculates the width of the specified page.
public JBIG2Globals	Returns: The decoded `JBIG2Globals`. processGlobals(ImageInputStream - The input stream of globals data. globalsInputStream) Decodes and returns the global segments.
public BufferedImage	read(int the index of the image to be retrieved. imageIndex, ImageReadParam an `ImageReadParam` used to control the reading process, or `null`. param) Implements abstract javax.imageio.ImageReader.read. Returns the decoded image of specified page considering the given `JBIG2ReadParam`s.
public Raster	readRaster(int the index of the image to be read. imageIndex, ImageReadParam an `ImageReadParam` used to control the reading process, or `null`. param) Overrides javax.imageio.ImageReader.readRaster. Returns a new `Raster` object containing the raw pixel data from the image stream, without any color conversion applied.
public void	setGlobals(JBIG2Globals - The globals to set. globals) Simply sets the globals.
public void	setInput(Object the `ImageInputStream` or other `Object` to use for future decoding. input, boolean if `true`, images and metadata may only be read in ascending order from this input source. seekForwardOnly, boolean if `true`, metadata may be ignored during reads. ignoreMetadata) Overrides javax.imageio.ImageReader.setInput. Sets the input source to use to the given `ImageInputStream` or other `Object`.

Inherited from javax.imageio.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

document	back to summary
private JBIG2Document document JBIG2 document to which we delegate current work.

globals	back to summary
private JBIG2Globals globals Globals are JBIG2 segments for PDF wide use.

JBIG2ImageReader	back to summary
public JBIG2ImageReader(ImageReaderSpi originatingProvider) throws IOException Parameters originatingProvider:ImageReaderSpi - The `ImageReaderSpi` that is invoking this constructor, or `null`. Exceptions IOException: if something went wrong while reading the provided stream. See Also `ImageReader#ImageReader(ImageReaderSpi)`

Method Detail

canReadRaster back to summary

canReadRaster	back to summary
public boolean canReadRaster() Overrides javax.imageio.ImageReader.canReadRaster. Doc from javax.imageio.ImageReader.canReadRaster. Returns `true` if this plug-in supports reading just a `Raster` of pixel data. If this method returns `false`, calls to `readRaster` or `readTileRaster` will throw an `UnsupportedOperationException`. The default implementation returns `false`. Returns:boolean `true` if this plug-in supports reading raw `Raster`s. Annotations @Override

public boolean canReadRaster()

Overrides javax.imageio.ImageReader.canReadRaster.

Doc from javax.imageio.ImageReader.canReadRaster.

Returns true if this plug-in supports reading just a Raster of pixel data. If this method returns false, calls to readRaster or readTileRaster will throw an UnsupportedOperationException.

The default implementation returns false.

Returns:boolean

true if this plug-in supports reading raw Rasters.

Annotations

@Override

getDefaultReadParam back to summary

getDefaultReadParam	back to summary
public JBIG2ReadParam getDefaultReadParam() Overrides javax.imageio.ImageReader.getDefaultReadParam. Doc from javax.imageio.ImageReader.getDefaultReadParam. Returns a default `ImageReadParam` object appropriate for this format. All subclasses should define a set of default values for all parameters and return them with this call. This method may be called before the input source is set. The default implementation constructs and returns a new `ImageReadParam` object that does not allow source scaling (i.e., it returns `new ImageReadParam()`. Returns:JBIG2ReadParam an `ImageReadParam` object which may be used to control the decoding process using a set of default settings. Annotations @Override See Also `ImageReader#getDefaultReadParam()`

public JBIG2ReadParam getDefaultReadParam()

Overrides javax.imageio.ImageReader.getDefaultReadParam.

Doc from javax.imageio.ImageReader.getDefaultReadParam.

Returns a default ImageReadParam object appropriate for this format. All subclasses should define a set of default values for all parameters and return them with this call. This method may be called before the input source is set.

The default implementation constructs and returns a new ImageReadParam object that does not allow source scaling (i.e., it returns new ImageReadParam().

Returns:JBIG2ReadParam

an ImageReadParam object which may be used to control the decoding process using a set of default settings.

Annotations

@Override

See Also

ImageReader#getDefaultReadParam()

getDefaultReadParam	back to summary
private JBIG2ReadParam getDefaultReadParam(final int imageIndex) Returns a default ImageReadParam object for a specific page. Parameters imageIndex:int - The page number.

getDefaultReadParam

back to summary

private JBIG2ReadParam getDefaultReadParam(final int imageIndex)

Returns a default ImageReadParam object for a specific page.

Parameters

imageIndex:int: - The page number.

getDocument	back to summary
private JBIG2Document getDocument() throws IOException

getGlobals	back to summary
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:JBIG2Globals Decoded global segments. Exceptions IOException: if an error occurs reading the height information from the input source.

getGlobals

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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:JBIG2Globals

Decoded global segments.

Exceptions

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

getHeight back to summary

getHeight	back to summary
public int getHeight(int imageIndex) throws IOException Implements abstract javax.imageio.ImageReader.getHeight. Calculates the height of the specified page. Parameters imageIndex:int - The image index. In this case it is the page number. Returns:int The height of the specified page or `0` if an error occurred. Annotations @Override Exceptions IOException: if an error occurs reading the height information from the input source.

public int getHeight(int imageIndex) throws IOException

Implements abstract javax.imageio.ImageReader.getHeight.

Calculates the height of the specified page.

Parameters

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

Returns:int

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

Annotations

@Override

Exceptions

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

getImageMetadata back to summary

public IIOMetadata getImageMetadata(int imageIndex) throws IOException

Implements abstract javax.imageio.ImageReader.getImageMetadata.

Simply returns the JBIG2ImageMetadata.

Parameters

imageIndex:int

Doc from javax.imageio.ImageReader.getImageMetadata.

the index of the image whose metadata is to be retrieved.

Returns:IIOMetadata

The associated JBIG2ImageMetadata.

Annotations

@Override

Exceptions

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

getImageTypes back to summary

getImageTypes	back to summary
public Iterator<ImageTypeSpecifier> getImageTypes(int imageIndex) throws IOException Implements abstract javax.imageio.ImageReader.getImageTypes. Returns the iterator for available image types. Parameters imageIndex:int - The page number. Returns:Iterator<ImageTypeSpecifier> An `Iterator` for available image types. Annotations @Override Exceptions IOException: if an error occurs reading the height information from the input source.

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

Implements abstract javax.imageio.ImageReader.getImageTypes.

Returns the iterator for available image types.

Parameters

imageIndex:int: - The page number.

Returns:Iterator<ImageTypeSpecifier>

An Iterator for available image types.

Annotations

@Override

Exceptions

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

getNumImages back to summary

getNumImages	back to summary
public int getNumImages(boolean allowSearch) throws IOException Implements abstract javax.imageio.ImageReader.getNumImages. Doc from javax.imageio.ImageReader.getNumImages. Returns the number of images, not including thumbnails, available from the current input source. Note that some image formats (such as animated GIF) do not specify how many images are present in the stream. Thus determining the number of images will require the entire stream to be scanned and may require memory for buffering. If images are to be processed in order, it may be more efficient to simply call `read` with increasing indices until an `IndexOutOfBoundsException` is thrown to indicate that no more images are available. The `allowSearch` parameter may be set to `false` to indicate that an exhaustive search is not desired; the return value will be `-1` to indicate that a search is necessary. If the input has been specified with `seekForwardOnly` set to `true`, this method throws an `IllegalStateException` if `allowSearch` is set to `true`. Parameters allowSearch:boolean if `true`, the true number of images will be returned even if a search is required. If `false`, the reader may return `-1` without performing the search. Returns:int the number of images, as an `int`, or `-1` if `allowSearch` is `false` and a search would be required. Annotations @Override Exceptions IOException: if an error occurs reading the information from the input source. See Also `ImageReader#getNumImages(boolean)`

public int getNumImages(boolean allowSearch) throws IOException

Implements abstract javax.imageio.ImageReader.getNumImages.

Doc from javax.imageio.ImageReader.getNumImages.

Returns the number of images, not including thumbnails, available from the current input source.

Note that some image formats (such as animated GIF) do not specify how many images are present in the stream. Thus determining the number of images will require the entire stream to be scanned and may require memory for buffering. If images are to be processed in order, it may be more efficient to simply call read with increasing indices until an IndexOutOfBoundsException is thrown to indicate that no more images are available. The allowSearch parameter may be set to false to indicate that an exhaustive search is not desired; the return value will be -1 to indicate that a search is necessary. If the input has been specified with seekForwardOnly set to true, this method throws an IllegalStateException if allowSearch is set to true.

Parameters

allowSearch:boolean: if true, the true number of images will be returned even if a search is required. If false, the reader may return -1 without performing the search.

Returns:int

the number of images, as an int, or -1 if allowSearch is false and a search would be required.

Annotations

@Override

Exceptions

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

See Also

ImageReader#getNumImages(boolean)

getPage	back to summary
private JBIG2Page getPage(int imageIndex) throws IOException

getStreamMetadata back to summary

public IIOMetadata getStreamMetadata()

Implements abstract javax.imageio.ImageReader.getStreamMetadata.

This ImageIO plugin doesn't record IIOMetadata.

Returns:IIOMetadata

null at every call.

Annotations

@Override

getWidth	back to summary
public int getWidth(int imageIndex) throws IOException Implements abstract javax.imageio.ImageReader.getWidth. Calculates the width of the specified page. Parameters imageIndex:int - The image index. In this case it is the page number. Returns:int The width of the specified page. Annotations @Override Exceptions IOException: if an error occurs reading the width information from the input source.

getWidth

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public int getWidth(int imageIndex) throws IOException

Implements abstract javax.imageio.ImageReader.getWidth.

Calculates the width of the specified page.

Parameters

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

Returns:int

The width of the specified page.

Annotations

@Override

Exceptions

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

processGlobals back to summary

processGlobals	back to summary
public JBIG2Globals processGlobals(ImageInputStream globalsInputStream) throws IOException Decodes and returns the global segments. Parameters globalsInputStream:ImageInputStream - The input stream of globals data. Returns:JBIG2Globals The decoded `JBIG2Globals`. Exceptions IOException: if an error occurs reading the height information from the input source.

public JBIG2Globals processGlobals(ImageInputStream globalsInputStream) throws IOException

Decodes and returns the global segments.

Parameters

globalsInputStream:ImageInputStream: - The input stream of globals data.

Returns:JBIG2Globals

The decoded JBIG2Globals.

Exceptions

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

read back to summary

read	back to summary
public BufferedImage read(int imageIndex, ImageReadParam param) throws IOException Implements abstract javax.imageio.ImageReader.read. Returns the decoded image of specified page considering the given `JBIG2ReadParam`s. Parameters imageIndex:int Doc from javax.imageio.ImageReader.read. the index of the image to be retrieved. param:ImageReadParam Doc from javax.imageio.ImageReader.read. an `ImageReadParam` used to control the reading process, or `null`. Returns:BufferedImage Doc from javax.imageio.ImageReader.read. the desired portion of the image as a `BufferedImage`. Annotations @Override Exceptions IOException: Doc from javax.imageio.ImageReader.read. if an error occurs during reading. See Also `ImageReader#read(int, ImageReadParam)`

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

Implements abstract javax.imageio.ImageReader.read.

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

Parameters

imageIndex:int

Doc from javax.imageio.ImageReader.read.

the index of the image to be retrieved.

param:ImageReadParam

Doc from javax.imageio.ImageReader.read.

an ImageReadParam used to control the reading process, or null.

Returns:BufferedImage

Doc from javax.imageio.ImageReader.read.

the desired portion of the image as a BufferedImage.

Annotations

@Override

Exceptions

IOException:

Doc from javax.imageio.ImageReader.read.

if an error occurs during reading.

See Also

ImageReader#read(int, ImageReadParam)

readRaster back to summary

readRaster	back to summary
public Raster readRaster(int imageIndex, ImageReadParam param) throws IOException Overrides javax.imageio.ImageReader.readRaster. Doc from javax.imageio.ImageReader.readRaster. Returns a new `Raster` object containing the raw pixel data from the image stream, without any color conversion applied. The application must determine how to interpret the pixel data by other means. Any destination or image-type parameters in the supplied `ImageReadParam` object are ignored, but all other parameters are used exactly as in the `read` method, except that any destination offset is used as a logical rather than a physical offset. The size of the returned `Raster` will always be that of the source region clipped to the actual image. Logical offsets in the stream itself are ignored. This method allows formats that normally apply a color conversion, such as JPEG, and formats that do not normally have an associated colorspace, such as remote sensing or medical imaging data, to provide access to raw pixel data. Any registered `readUpdateListener`s are ignored, as there is no `BufferedImage`, but all other listeners are called exactly as they are for the `read` method. If `canReadRaster()` returns `false`, this method throws an `UnsupportedOperationException`. If the supplied `ImageReadParam` contains optional setting values not supported by this reader (e.g. source render size or any format-specific settings), they will be ignored. The default implementation throws an `UnsupportedOperationException`. Parameters imageIndex:int the index of the image to be read. param:ImageReadParam an `ImageReadParam` used to control the reading process, or `null`. Returns:Raster the desired portion of the image as a `Raster`. Annotations @Override Exceptions IOException: if an error occurs during reading.

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

Overrides javax.imageio.ImageReader.readRaster.

Doc from javax.imageio.ImageReader.readRaster.

Returns a new Raster object containing the raw pixel data from the image stream, without any color conversion applied. The application must determine how to interpret the pixel data by other means. Any destination or image-type parameters in the supplied ImageReadParam object are ignored, but all other parameters are used exactly as in the read method, except that any destination offset is used as a logical rather than a physical offset. The size of the returned Raster will always be that of the source region clipped to the actual image. Logical offsets in the stream itself are ignored.

This method allows formats that normally apply a color conversion, such as JPEG, and formats that do not normally have an associated colorspace, such as remote sensing or medical imaging data, to provide access to raw pixel data.

Any registered readUpdateListeners are ignored, as there is no BufferedImage, but all other listeners are called exactly as they are for the read method.

If canReadRaster() returns false, this method throws an UnsupportedOperationException.

If the supplied ImageReadParam contains optional setting values not supported by this reader (e.g. source render size or any format-specific settings), they will be ignored.

The default implementation throws an UnsupportedOperationException.

Parameters

imageIndex:int: the index of the image to be read.
param:ImageReadParam: an ImageReadParam used to control the reading process, or null.

Returns:Raster

the desired portion of the image as a Raster.

Annotations

@Override

Exceptions

IOException:: if an error occurs during reading.

setGlobals	back to summary
public void setGlobals(JBIG2Globals globals) throws IOException Simply sets the globals. Parameters globals:JBIG2Globals - The globals to set. Exceptions IOException: if an error occurs

setGlobals

back to summary

public void setGlobals(JBIG2Globals globals) throws IOException

Simply sets the globals.

Parameters

globals:JBIG2Globals: - The globals to set.

Exceptions

IOException:: if an error occurs

setInput back to summary

setInput	back to summary
public void setInput(Object input, boolean seekForwardOnly, boolean ignoreMetadata) Overrides javax.imageio.ImageReader.setInput. Doc from javax.imageio.ImageReader.setInput. Sets the input source to use to the given `ImageInputStream` or other `Object`. The input source must be set before any of the query or read methods are used. If `input` is `null`, any currently set input source will be removed. In any case, the value of `minIndex` will be initialized to 0. The `seekForwardOnly` parameter controls whether the value returned by `getMinIndex` will be increased as each image (or thumbnail, or image metadata) is read. If `seekForwardOnly` is true, then a call to `read(index)` will throw an `IndexOutOfBoundsException` if `index < this.minIndex`; otherwise, the value of `minIndex` will be set to `index`. If `seekForwardOnly` is `false`, the value of `minIndex` will remain 0 regardless of any read operations. The `ignoreMetadata` parameter, if set to `true`, allows the reader to disregard any metadata encountered during the read. Subsequent calls to the `getStreamMetadata` and `getImageMetadata` methods may return `null`, and an `IIOImage` returned from `readAll` may return `null` from their `getMetadata` method. Setting this parameter may allow the reader to work more efficiently. The reader may choose to disregard this setting and return metadata normally. Subclasses should take care to remove any cached information based on the previous stream, such as header information or partially decoded image data. Use of a general `Object` other than an `ImageInputStream` is intended for readers that interact directly with a capture device or imaging protocol. The set of legal classes is advertised by the reader's service provider's `getInputTypes` method; most readers will return a single-element array containing only `ImageInputStream.class` to indicate that they accept only an `ImageInputStream`. The default implementation checks the `input` argument against the list returned by `originatingProvider.getInputTypes()` and fails if the argument is not an instance of one of the classes in the list. If the originating provider is set to `null`, the input is accepted only if it is an `ImageInputStream`. Parameters input:Object the `ImageInputStream` or other `Object` to use for future decoding. seekForwardOnly:boolean if `true`, images and metadata may only be read in ascending order from this input source. ignoreMetadata:boolean if `true`, metadata may be ignored during reads. Annotations @Override See Also `ImageReader#setInput(Object, boolean, boolean)`

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

Overrides javax.imageio.ImageReader.setInput.

Doc from javax.imageio.ImageReader.setInput.

Sets the input source to use to the given ImageInputStream or other Object. The input source must be set before any of the query or read methods are used. If input is null, any currently set input source will be removed. In any case, the value of minIndex will be initialized to 0.

The seekForwardOnly parameter controls whether the value returned by getMinIndex will be increased as each image (or thumbnail, or image metadata) is read. If seekForwardOnly is true, then a call to read(index) will throw an IndexOutOfBoundsException if index < this.minIndex; otherwise, the value of minIndex will be set to index. If seekForwardOnly is false, the value of minIndex will remain 0 regardless of any read operations.

The ignoreMetadata parameter, if set to true, allows the reader to disregard any metadata encountered during the read. Subsequent calls to the getStreamMetadata and getImageMetadata methods may return null, and an IIOImage returned from readAll may return null from their getMetadata method. Setting this parameter may allow the reader to work more efficiently. The reader may choose to disregard this setting and return metadata normally.

Subclasses should take care to remove any cached information based on the previous stream, such as header information or partially decoded image data.

Use of a general Object other than an ImageInputStream is intended for readers that interact directly with a capture device or imaging protocol. The set of legal classes is advertised by the reader's service provider's getInputTypes method; most readers will return a single-element array containing only ImageInputStream.class to indicate that they accept only an ImageInputStream.

The default implementation checks the input argument against the list returned by originatingProvider.getInputTypes() and fails if the argument is not an instance of one of the classes in the list. If the originating provider is set to null, the input is accepted only if it is an ImageInputStream.

Parameters

input:Object: the ImageInputStream or other Object to use for future decoding.
seekForwardOnly:boolean: if true, images and metadata may only be read in ascending order from this input source.
ignoreMetadata:boolean: if true, metadata may be ignored during reads.

Annotations

@Override

public Class JBIG2ImageReader

Field Summary

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Field Detail

Constructor Detail

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