Class GIFImageWriter

java.lang.Object

javax.imageio.ImageWriter

com.github.jaiimageio.impl.plugins.gif.GIFImageWriter

All Implemented Interfaces:

ImageTranscoder

public class GIFImageWriter
extends ImageWriter

Field Summary

Fields

Modifier and Type	Field	Description
private static final boolean	DEBUG
(package private) static final String	IMAGE_METADATA_NAME
private int	imageIndex	The index of the image being written.
private boolean	isWritingSequence	Whether a sequence is being written.
(package private) static final String	STANDARD_METADATA_NAME
private ImageOutputStream	stream	The output case to an ImageOutputStream.
(package private) static final String	STREAM_METADATA_NAME
private GIFWritableStreamMetadata	theStreamMetadata	The stream metadata of a sequence.
private boolean	wroteSequenceHeader	Whether the header has been written.

Fields inherited from class ImageWriter

availableLocales, locale, originatingProvider, output, progressListeners, warningListeners, warningLocales

Constructor Summary

Constructors

Constructor	Description
GIFImageWriter(GIFImageWriterSpi originatingProvider)

Method Summary

Modifier and Type	Method	Description
boolean	canWriteSequence()
private static void	computeRegions(Rectangle sourceBounds, Dimension destSize, ImageWriteParam p)	Compute the source region and destination dimensions taking any parameter settings into account.
IIOMetadata	convertImageMetadata(IIOMetadata inData, ImageTypeSpecifier imageType, ImageWriteParam param)	Creates a default image metadata object and merges in the supplied metadata.
private void	convertMetadata(String metadataFormatName, IIOMetadata inData, IIOMetadata outData)	Merges inData into outData.
IIOMetadata	convertStreamMetadata(IIOMetadata inData, ImageWriteParam param)	Creates a default stream metadata object and merges in the supplied metadata.
private static byte[]	createColorTable(ColorModel colorModel, SampleModel sampleModel)	Create a color table from the image ColorModel and SampleModel.
void	endWriteSequence()
IIOMetadata	getDefaultImageMetadata(ImageTypeSpecifier imageType, ImageWriteParam param)
IIOMetadata	getDefaultStreamMetadata(ImageWriteParam param)
ImageWriteParam	getDefaultWriteParam()
private static int	getGifPaletteSize(int x)	According do GIF specification size of clor table (palette here) must be in range from 2 to 256 and must be power of 2.
private static int	getNumBits(int value)	The number of bits represented by the value which should be a legal length for a color table.
private boolean	needToCreateIndex(RenderedImage image)
void	prepareWriteSequence(IIOMetadata streamMetadata)
void	reset()
private void	resetLocal()	Resets locally defined instance variables.
void	setOutput(Object output)
private void	write(boolean writeHeader, boolean writeTrailer, IIOMetadata sm, IIOImage iioimage, ImageWriteParam p)	Writes any extension blocks, the Image Descriptor, the image data, and optionally the header (Signature and Logical Screen Descriptor) and trailer (Block Terminator).
void	write(IIOMetadata sm, IIOImage iioimage, ImageWriteParam p)
private void	writeApplicationExtension(GIFWritableImageMetadata im)
private void	writeBlocks(byte[] data)
private void	writeCommentExtension(GIFWritableImageMetadata im)
private void	writeGraphicControlExtension(int disposalMethod, boolean userInputFlag, boolean transparentColorFlag, int delayTime, int transparentColorIndex)
private void	writeGraphicControlExtension(GIFWritableImageMetadata im)
private void	writeHeader(String version, int logicalScreenWidth, int logicalScreenHeight, int colorResolution, int pixelAspectRatio, int backgroundColorIndex, boolean sortFlag, int bitsPerPixel, byte[] globalColorTable)
private void	writeHeader(IIOMetadata streamMetadata, int bitsPerPixel)
private void	writeImage(RenderedImage image, GIFWritableImageMetadata imageMetadata, ImageWriteParam param, byte[] globalColorTable, Rectangle sourceBounds, Dimension destSize)	Writes any extension blocks, the Image Descriptor, and the image data
private void	writeImageDescriptor(int imageLeftPosition, int imageTopPosition, int imageWidth, int imageHeight, boolean interlaceFlag, boolean sortFlag, int bitsPerPixel, byte[] localColorTable)
private void	writeImageDescriptor(GIFWritableImageMetadata imageMetadata, int bitsPerPixel)
private void	writePlainTextExtension(GIFWritableImageMetadata im)
private void	writeRasterData(RenderedImage image, Rectangle sourceBounds, Dimension destSize, ImageWriteParam param, boolean interlaceFlag)
private void	writeRows(RenderedImage image, LZWCompressor compressor, int sx, int sdx, int sy, int sdy, int sw, int dy, int ddy, int dw, int dh, int numRowsWritten, int progressReportRowPeriod)
private void	writeRowsOpt(byte[] data, int offset, int lineStride, LZWCompressor compressor, int dy, int ddy, int dw, int dh, int numRowsWritten, int progressReportRowPeriod)
void	writeToSequence(IIOImage image, ImageWriteParam param)
private void	writeTrailer()

Methods inherited from class ImageWriter

abort, abortRequested, addIIOWriteProgressListener, addIIOWriteWarningListener, canInsertEmpty, canInsertImage, canRemoveImage, canReplaceImageMetadata, canReplacePixels, canReplaceStreamMetadata, canWriteEmpty, canWriteRasters, clearAbortRequest, dispose, endInsertEmpty, endReplacePixels, endWriteEmpty, getAvailableLocales, getLocale, getNumThumbnailsSupported, getOriginatingProvider, getOutput, getPreferredThumbnailSizes, prepareInsertEmpty, prepareReplacePixels, prepareWriteEmpty, processImageComplete, processImageProgress, processImageStarted, processThumbnailComplete, processThumbnailProgress, processThumbnailStarted, processWarningOccurred, processWarningOccurred, processWriteAborted, removeAllIIOWriteProgressListeners, removeAllIIOWriteWarningListeners, removeIIOWriteProgressListener, removeIIOWriteWarningListener, removeImage, replaceImageMetadata, replacePixels, replacePixels, replaceStreamMetadata, setLocale, write, write, writeInsert

Methods inherited from class Object

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

Field Details

DEBUG

private static final boolean DEBUG

See Also:

• Constant Field Values

STANDARD_METADATA_NAME

static final String STANDARD_METADATA_NAME

See Also:

• Constant Field Values

STREAM_METADATA_NAME

static final String STREAM_METADATA_NAME

See Also:

• Constant Field Values

IMAGE_METADATA_NAME

static final String IMAGE_METADATA_NAME

See Also:

• Constant Field Values

stream

private ImageOutputStream stream

The output case to an ImageOutputStream.

isWritingSequence

private boolean isWritingSequence

Whether a sequence is being written.

wroteSequenceHeader

private boolean wroteSequenceHeader

Whether the header has been written.

theStreamMetadata

private GIFWritableStreamMetadata theStreamMetadata

The stream metadata of a sequence.

imageIndex

private int imageIndex

The index of the image being written.

Constructor Details

GIFImageWriter

public GIFImageWriter(GIFImageWriterSpi originatingProvider)

Method Details

getNumBits

private static int getNumBits(int value)
                       throws IOException

The number of bits represented by the value which should be a legal length for a color table.

Throws:

IOException

computeRegions

private static void computeRegions(Rectangle sourceBounds,
 Dimension destSize,
 ImageWriteParam p)

Compute the source region and destination dimensions taking any parameter settings into account.

createColorTable

private static byte[] createColorTable(ColorModel colorModel,
 SampleModel sampleModel)

Create a color table from the image ColorModel and SampleModel.

getGifPaletteSize

private static int getGifPaletteSize(int x)

According do GIF specification size of clor table (palette here) must be in range from 2 to 256 and must be power of 2.

canWriteSequence

public boolean canWriteSequence()

Overrides:

canWriteSequence in class ImageWriter

convertMetadata

private void convertMetadata(String metadataFormatName,
 IIOMetadata inData,
 IIOMetadata outData)

Merges inData into outData. The supplied metadata format name is attempted first and failing that the standard metadata format name is attempted.

convertStreamMetadata

public IIOMetadata convertStreamMetadata(IIOMetadata inData,
 ImageWriteParam param)

Creates a default stream metadata object and merges in the supplied metadata.

Specified by:

convertStreamMetadata in interface ImageTranscoder

Specified by:

convertStreamMetadata in class ImageWriter

convertImageMetadata

public IIOMetadata convertImageMetadata(IIOMetadata inData,
 ImageTypeSpecifier imageType,
 ImageWriteParam param)

Creates a default image metadata object and merges in the supplied metadata.

Specified by:

convertImageMetadata in interface ImageTranscoder

Specified by:

convertImageMetadata in class ImageWriter

endWriteSequence

public void endWriteSequence()
                      throws IOException

Overrides:

endWriteSequence in class ImageWriter

Throws:

IOException

getDefaultImageMetadata

public IIOMetadata getDefaultImageMetadata(ImageTypeSpecifier imageType,
 ImageWriteParam param)

Specified by:

getDefaultImageMetadata in class ImageWriter

getDefaultStreamMetadata

public IIOMetadata getDefaultStreamMetadata(ImageWriteParam param)

Specified by:

getDefaultStreamMetadata in class ImageWriter

getDefaultWriteParam

public ImageWriteParam getDefaultWriteParam()

Overrides:

getDefaultWriteParam in class ImageWriter

prepareWriteSequence

public void prepareWriteSequence(IIOMetadata streamMetadata)
                          throws IOException

Overrides:

prepareWriteSequence in class ImageWriter

Throws:

IOException

reset

public void reset()

Overrides:

reset in class ImageWriter

resetLocal

private void resetLocal()

Resets locally defined instance variables.

setOutput

public void setOutput(Object output)

Overrides:

setOutput in class ImageWriter

write

public void write(IIOMetadata sm,
 IIOImage iioimage,
 ImageWriteParam p)
           throws IOException

Specified by:

write in class ImageWriter

Throws:

IOException

writeToSequence

public void writeToSequence(IIOImage image,
 ImageWriteParam param)
                     throws IOException

Overrides:

writeToSequence in class ImageWriter

Throws:

IOException

needToCreateIndex

private boolean needToCreateIndex(RenderedImage image)

write

private void write(boolean writeHeader,
 boolean writeTrailer,
 IIOMetadata sm,
 IIOImage iioimage,
 ImageWriteParam p)
            throws IOException

Writes any extension blocks, the Image Descriptor, the image data, and optionally the header (Signature and Logical Screen Descriptor) and trailer (Block Terminator).

Parameters:

writeHeader - Whether to write the header.

writeTrailer - Whether to write the trailer.

sm - The stream metadata or null if writeHeader is false.

iioimage - The image and image metadata.

p - The write parameters.

Throws:

IllegalArgumentException - if the number of bands is not 1.

IllegalArgumentException - if the number of bits per sample is greater than 8.

IllegalArgumentException - if the color component size is greater than 8.

IllegalArgumentException - if writeHeader is true and sm is null.

IllegalArgumentException - if writeHeader is false and a sequence is not being written.

IOException

writeImage

private void writeImage(RenderedImage image,
 GIFWritableImageMetadata imageMetadata,
 ImageWriteParam param,
 byte[] globalColorTable,
 Rectangle sourceBounds,
 Dimension destSize)
                 throws IOException

Writes any extension blocks, the Image Descriptor, and the image data

Parameters:

image - The image.

imageMetadata - The Image metadata.

param - The write parameters.

globalColorTable - The Global Color Table.

sourceBounds - The source region.

destSize - The destination dimensions.

Throws:

IOException

writeRows

private void writeRows(RenderedImage image,
 LZWCompressor compressor,
 int sx,
 int sdx,
 int sy,
 int sdy,
 int sw,
 int dy,
 int ddy,
 int dw,
 int dh,
 int numRowsWritten,
 int progressReportRowPeriod)
                throws IOException

Throws:

IOException

writeRowsOpt

private void writeRowsOpt(byte[] data,
 int offset,
 int lineStride,
 LZWCompressor compressor,
 int dy,
 int ddy,
 int dw,
 int dh,
 int numRowsWritten,
 int progressReportRowPeriod)
                   throws IOException

Throws:

IOException

writeRasterData

private void writeRasterData(RenderedImage image,
 Rectangle sourceBounds,
 Dimension destSize,
 ImageWriteParam param,
 boolean interlaceFlag)
                      throws IOException

Throws:

IOException

writeHeader

private void writeHeader(String version,
 int logicalScreenWidth,
 int logicalScreenHeight,
 int colorResolution,
 int pixelAspectRatio,
 int backgroundColorIndex,
 boolean sortFlag,
 int bitsPerPixel,
 byte[] globalColorTable)
                  throws IOException

Throws:

IOException

writeHeader

private void writeHeader(IIOMetadata streamMetadata,
 int bitsPerPixel)
                  throws IOException

Throws:

IOException

writeGraphicControlExtension

private void writeGraphicControlExtension(int disposalMethod,
 boolean userInputFlag,
 boolean transparentColorFlag,
 int delayTime,
 int transparentColorIndex)
                                   throws IOException

Throws:

IOException

writeGraphicControlExtension

private void writeGraphicControlExtension(GIFWritableImageMetadata im)
                                   throws IOException

Throws:

IOException

writeBlocks

private void writeBlocks(byte[] data)
                  throws IOException

Throws:

IOException

writePlainTextExtension

private void writePlainTextExtension(GIFWritableImageMetadata im)
                              throws IOException

Throws:

IOException

writeApplicationExtension

private void writeApplicationExtension(GIFWritableImageMetadata im)
                                throws IOException

Throws:

IOException

writeCommentExtension

private void writeCommentExtension(GIFWritableImageMetadata im)
                            throws IOException

Throws:

IOException

writeImageDescriptor

private void writeImageDescriptor(int imageLeftPosition,
 int imageTopPosition,
 int imageWidth,
 int imageHeight,
 boolean interlaceFlag,
 boolean sortFlag,
 int bitsPerPixel,
 byte[] localColorTable)
                           throws IOException

Throws:

IOException

writeImageDescriptor

private void writeImageDescriptor(GIFWritableImageMetadata imageMetadata,
 int bitsPerPixel)
                           throws IOException

Throws:

IOException

writeTrailer

private void writeTrailer()
                   throws IOException

Throws:

IOException