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javax.imageio

public Class ImageWriteParam

extends IIOParam
Class Inheritance
Known Direct Subclasses
javax.imageio.plugins.bmp.BMPImageWriteParam, javax.imageio.plugins.jpeg.JPEGImageWriteParam, com.sun.imageio.plugins.gif.GIFImageWriteParam, com.sun.imageio.plugins.png.PNGImageWriteParam, com.sun.imageio.plugins.tiff.TIFFImageWriteParam
Imports
java.awt.Dimension, java.util.Locale
A class describing how a stream is to be encoded. Instances of this class or its subclasses are used to supply prescriptive "how-to" information to instances of ImageWriter.

A plug-in for a specific image format may define a subclass of this class, and return objects of that class from the getDefaultWriteParam method of its ImageWriter implementation. For example, the built-in JPEG writer plug-in will return instances of javax.imageio.plugins.jpeg.JPEGImageWriteParam.

The region of the image to be written is determined by first intersecting the actual bounds of the image with the rectangle specified by IIOParam.setSourceRegion, if any. If the resulting rectangle has a width or height of zero, the writer will throw an IIOException. If the intersection is non-empty, writing will commence with the first subsampled pixel and include additional pixels within the intersected bounds according to the horizontal and vertical subsampling factors specified by IIOParam.setSourceSubsampling.

Individual features such as tiling, progressive encoding, and compression may be set in one of four modes. MODE_DISABLED disables the features; MODE_DEFAULT enables the feature with writer-controlled parameter values; MODE_EXPLICIT enables the feature and allows the use of a set method to provide additional parameters; and MODE_COPY_FROM_METADATA copies relevant parameter values from the stream and image metadata objects passed to the writer. The default for all features is MODE_COPY_FROM_METADATA. Non-standard features supplied in subclasses are encouraged, but not required to use a similar scheme.

Plug-in writers may extend the functionality of ImageWriteParam by providing a subclass that implements additional, plug-in specific interfaces. It is up to the plug-in to document what interfaces are available and how they are to be used. Writers will silently ignore any extended features of an ImageWriteParam subclass of which they are not aware. Also, they may ignore any optional features that they normally disable when creating their own ImageWriteParam instances via getDefaultWriteParam.

Note that unless a query method exists for a capability, it must be supported by all ImageWriter implementations (e.g. progressive encoding is optional, but subsampling must be supported).

See Also
ImageReadParam

Field Summary

Modifier and TypeField and Description
protected boolean
canOffsetTiles

A boolean that is true if this ImageWriteParam allows tiling grid offset parameters to be set.

protected boolean
canWriteCompressed

A boolean that is true if this writer can write images using compression.

protected boolean
canWriteProgressive

A boolean that is true if this ImageWriteParam allows images to be written as a progressive sequence of increasing quality passes.

protected boolean
canWriteTiles

A boolean that is true if this ImageWriteParam allows tile width and tile height parameters to be set.

protected int
compressionMode

The mode controlling compression settings, which must be set to one of the four MODE_* values.

protected float
compressionQuality

A float containing the current compression quality setting.

protected String
compressionType

A String containing the name of the current compression type, or null if none is set.

protected String[]
compressionTypes

An array of Strings containing the names of the available compression types.

protected Locale
locale

A Locale to be used to localize compression type names and quality descriptions, or null to use a default Locale.

private static final int
MAX_MODE

public static final int
MODE_COPY_FROM_METADATA

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, or setCompressionMode to enable that feature for future writes.

public static final int
MODE_DEFAULT

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, and setCompressionMode to enable that feature for future writes.

public static final int
MODE_DISABLED

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, and setCompressionMode to disable a feature for future writes.

public static final int
MODE_EXPLICIT

A constant value that may be passed into methods such as setTilingMode or setCompressionMode to enable a feature for future writes.

protected Dimension[]
preferredTileSizes

An array of preferred tile size range pairs.

protected int
progressiveMode

The mode controlling progressive encoding, which must be set to one of the four MODE_* values, except MODE_EXPLICIT.

protected int
tileGridXOffset

The amount by which the tile grid origin should be offset horizontally from the image origin if tiling has been set, or 0 otherwise.

protected int
tileGridYOffset

The amount by which the tile grid origin should be offset vertically from the image origin if tiling has been set, or 0 otherwise.

protected int
tileHeight

The height of each tile if tiling has been set, or 0 otherwise.

protected int
tileWidth

The width of each tile if tiling has been set, or 0 otherwise.

protected int
tilingMode

The mode controlling tiling settings, which Must be set to one of the four MODE_* values.

protected boolean
tilingSet

A boolean that is true if tiling parameters have been specified.

Inherited from javax.imageio.IIOParam:
controllerdefaultControllerdestinationOffsetdestinationTypesourceBandssourceRegionsourceXSubsamplingsourceYSubsamplingsubsamplingXOffsetsubsamplingYOffset

Constructor Summary

AccessConstructor and Description
protected
ImageWriteParam()

Constructs an empty ImageWriteParam.

public
ImageWriteParam(Locale
a Locale to be used to localize compression type names and quality descriptions, or null.
locale)

Constructs an ImageWriteParam set to use a given Locale.

Method Summary

Modifier and TypeMethod and Description
public boolean

Returns:

true if the writer supports non-zero tile offsets.
canOffsetTiles()

Returns true if the writer can perform tiling with non-zero grid offsets while writing.

public boolean

Returns:

true if the writer supports compression.
canWriteCompressed()

Returns true if this writer supports compression.

public boolean

Returns:

true if the writer supports progressive encoding.
canWriteProgressive()

Returns true if the writer can write out images as a series of passes of progressively increasing quality.

public boolean

Returns:

true if the writer supports tiling.
canWriteTiles()

Returns true if the writer can perform tiling while writing.

private static Dimension[]
clonePreferredTileSizes(Dimension[] sizes)

public float

Returns:

an estimate of the compressed bit rate, or -1.0F if no estimate is available.
getBitRate(float
the quality setting whose bit rate is to be queried.
quality)

Returns a float indicating an estimate of the number of bits of output data for each bit of input image data at the given quality level.

public int

Returns:

the current compression mode.
getCompressionMode()

Returns the current compression mode, if compression is supported.

public float

Returns:

the current compression quality setting.
getCompressionQuality()

Returns the current compression quality setting.

public String[]

Returns:

an array of Strings containing localized descriptions of the compression quality levels.
getCompressionQualityDescriptions()

Returns an array of Strings that may be used along with getCompressionQualityValues as part of a user interface for setting or displaying the compression quality level.

public float[]

Returns:

an array of floats indicating the boundaries between the compression quality levels as described by the Strings from getCompressionQualityDescriptions.
getCompressionQualityValues()

Returns an array of floats that may be used along with getCompressionQualityDescriptions as part of a user interface for setting or displaying the compression quality level.

public String

Returns:

the current compression type as a String, or null if no type is set.
getCompressionType()

Returns the currently set compression type, or null if none has been set.

public String[]

Returns:

an array of Strings containing the (non-localized) names of available compression types, or null.
getCompressionTypes()

Returns a list of available compression types, as an array or Strings, or null if a compression type may not be chosen using these interfaces.

public Locale

Returns:

the current Locale, or null.
getLocale()

Returns the currently set Locale, or null if only a default Locale is supported.

public String

Returns:

a String containing a localized version of the name of the current compression type.
getLocalizedCompressionTypeName()

Returns a localized version of the name of the current compression type, using the Locale returned by getLocale.

public Dimension[]

Returns:

an array of Dimensions with an even length of at least two, or null.
getPreferredTileSizes()

Returns an array of Dimensions indicating the legal size ranges for tiles as they will be encoded in the output file or stream.

public int

Returns:

the current mode for progressive encoding.
getProgressiveMode()

Returns the current mode for writing the stream in a progressive manner.

public int

Returns:

the tile grid X offset to be used for encoding.
getTileGridXOffset()

Returns the horizontal tile grid offset of an image as it will be written to the output stream.

public int

Returns:

the tile grid Y offset to be used for encoding.
getTileGridYOffset()

Returns the vertical tile grid offset of an image as it will be written to the output stream.

public int

Returns:

the tile height to be used for encoding.
getTileHeight()

Returns the height of each tile in an image as it will be written to the output stream.

public int

Returns:

the tile width to be used for encoding.
getTileWidth()

Returns the width of each tile in an image as it will be written to the output stream.

public int

Returns:

the current tiling mode.
getTilingMode()

Returns the current tiling mode, if tiling is supported.

public boolean

Returns:

true if the current compression type is lossless.
isCompressionLossless()

Returns true if the current compression type provides lossless compression.

public void
setCompressionMode(int
The mode for setting compression in the output stream.
mode)

Specifies whether compression is to be performed, and if so how compression parameters are to be determined.

public void
setCompressionQuality(float
a float between 0 and 1 indicating the desired quality level.
quality)

Sets the compression quality to a value between 0 and 1.

public void
setCompressionType(String
one of the Strings returned by getCompressionTypes, or null to remove any previous setting.
compressionType)

Sets the compression type to one of the values indicated by getCompressionTypes.

public void
setProgressiveMode(int
The mode for setting progression in the output stream.
mode)

Specifies that the writer is to write the image out in a progressive mode such that the stream will contain a series of scans of increasing quality.

public void
setTiling(int
the width of each tile.
tileWidth, int
the height of each tile.
tileHeight, int
the horizontal offset of the tile grid.
tileGridXOffset, int
the vertical offset of the tile grid.
tileGridYOffset)

Specifies that the image should be tiled in the output stream.

public void
setTilingMode(int
The mode to use for tiling.
mode)

Determines whether the image will be tiled in the output stream and, if it will, how the tiling parameters will be determined.

public void
unsetCompression()

Removes any previous compression type and quality settings.

public void
unsetTiling()

Removes any previous tile grid parameters specified by calls to setTiling.

Inherited from javax.imageio.IIOParam:
activateControllergetControllergetDefaultControllergetDestinationOffsetgetDestinationTypegetSourceBandsgetSourceRegiongetSourceXSubsamplinggetSourceYSubsamplinggetSubsamplingXOffsetgetSubsamplingYOffsethasControllersetControllersetDestinationOffsetsetDestinationTypesetSourceBandssetSourceRegionsetSourceSubsampling

Field Detail

canOffsetTilesback to summary
protected boolean canOffsetTiles

A boolean that is true if this ImageWriteParam allows tiling grid offset parameters to be set. By default, the value is false. Subclasses must set the value manually.

Subclasses that do not support writing tiles, or that support writing but not offsetting tiles must ensure that this value is set to false.

canWriteCompressedback to summary
protected boolean canWriteCompressed

A boolean that is true if this writer can write images using compression. By default, the value is false. Subclasses must set the value manually.

Subclasses that do not support compression must ensure that this value is set to false.

canWriteProgressiveback to summary
protected boolean canWriteProgressive

A boolean that is true if this ImageWriteParam allows images to be written as a progressive sequence of increasing quality passes. By default, the value is false. Subclasses must set the value manually.

Subclasses that do not support progressive encoding must ensure that this value is set to false.

canWriteTilesback to summary
protected boolean canWriteTiles

A boolean that is true if this ImageWriteParam allows tile width and tile height parameters to be set. By default, the value is false. Subclasses must set the value manually.

Subclasses that do not support writing tiles should ensure that this value is set to false.

compressionModeback to summary
protected int compressionMode

The mode controlling compression settings, which must be set to one of the four MODE_* values. The default is MODE_COPY_FROM_METADATA.

Subclasses that do not support compression may ignore this value.

See Also
MODE_DISABLED, MODE_EXPLICIT, MODE_COPY_FROM_METADATA, MODE_DEFAULT, setCompressionMode, getCompressionMode
compressionQualityback to summary
protected float compressionQuality

A float containing the current compression quality setting. The initial value is 1.0F.

Subclasses that do not support compression may ignore this value.

compressionTypeback to summary
protected String compressionType

A String containing the name of the current compression type, or null if none is set.

Subclasses that do not support compression may ignore this value.

compressionTypesback to summary
protected String[] compressionTypes

An array of Strings containing the names of the available compression types. Subclasses must set the value manually.

Subclasses that do not support compression may ignore this value.

localeback to summary
protected Locale locale

A Locale to be used to localize compression type names and quality descriptions, or null to use a default Locale. Subclasses must set the value manually.

MAX_MODEback to summary
private static final int MAX_MODE
MODE_COPY_FROM_METADATAback to summary
public static final int MODE_COPY_FROM_METADATA

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, or setCompressionMode to enable that feature for future writes. That is, when this mode is enabled the stream will be tiled, progressive, or compressed based on the contents of stream and/or image metadata passed into the write operation, and any relevant accessor methods will throw an IllegalStateException.

This is the default mode for all features, so that a read including metadata followed by a write including metadata will preserve as much information as possible.

See Also
MODE_DISABLED, MODE_EXPLICIT, MODE_DEFAULT, setProgressiveMode, getProgressiveMode, setTilingMode, getTilingMode, setCompressionMode, getCompressionMode
MODE_DEFAULTback to summary
public static final int MODE_DEFAULT

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, and setCompressionMode to enable that feature for future writes. That is, when this mode is enabled the stream will be tiled, progressive, or compressed according to a sensible default chosen internally by the writer in a plug-in dependent way, and the relevant accessor methods will throw an IllegalStateException.

See Also
MODE_DISABLED, MODE_EXPLICIT, MODE_COPY_FROM_METADATA, setProgressiveMode, getProgressiveMode, setTilingMode, getTilingMode, setCompressionMode, getCompressionMode
MODE_DISABLEDback to summary
public static final int MODE_DISABLED

A constant value that may be passed into methods such as setTilingMode, setProgressiveMode, and setCompressionMode to disable a feature for future writes. That is, when this mode is set the stream will not be tiled, progressive, or compressed, and the relevant accessor methods will throw an IllegalStateException.

See Also
MODE_EXPLICIT, MODE_COPY_FROM_METADATA, MODE_DEFAULT, setProgressiveMode, getProgressiveMode, setTilingMode, getTilingMode, setCompressionMode, getCompressionMode
MODE_EXPLICITback to summary
public static final int MODE_EXPLICIT

A constant value that may be passed into methods such as setTilingMode or setCompressionMode to enable a feature for future writes. That is, when this mode is set the stream will be tiled or compressed according to additional information supplied to the corresponding set methods in this class and retrievable from the corresponding get methods. Note that this mode is not supported for progressive output.

See Also
MODE_DISABLED, MODE_COPY_FROM_METADATA, MODE_DEFAULT, setProgressiveMode, getProgressiveMode, setTilingMode, getTilingMode, setCompressionMode, getCompressionMode
preferredTileSizesback to summary
protected Dimension[] preferredTileSizes

An array of preferred tile size range pairs. The default value is null, which indicates that there are no preferred sizes. If the value is non-null, it must have an even length of at least two.

Subclasses that do not support writing tiles may ignore this value.

See Also
getPreferredTileSizes
progressiveModeback to summary
protected int progressiveMode

The mode controlling progressive encoding, which must be set to one of the four MODE_* values, except MODE_EXPLICIT. The default is MODE_COPY_FROM_METADATA.

Subclasses that do not support progressive encoding may ignore this value.

See Also
MODE_DISABLED, MODE_EXPLICIT, MODE_COPY_FROM_METADATA, MODE_DEFAULT, setProgressiveMode, getProgressiveMode
tileGridXOffsetback to summary
protected int tileGridXOffset

The amount by which the tile grid origin should be offset horizontally from the image origin if tiling has been set, or 0 otherwise. The initial value is 0.

Subclasses that do not support offsetting tiles may ignore this value.

tileGridYOffsetback to summary
protected int tileGridYOffset

The amount by which the tile grid origin should be offset vertically from the image origin if tiling has been set, or 0 otherwise. The initial value is 0.

Subclasses that do not support offsetting tiles may ignore this value.

tileHeightback to summary
protected int tileHeight

The height of each tile if tiling has been set, or 0 otherwise. The initial value is 0.

Subclasses that do not support tiling may ignore this value.

tileWidthback to summary
protected int tileWidth

The width of each tile if tiling has been set, or 0 otherwise.

Subclasses that do not support tiling may ignore this value.

tilingModeback to summary
protected int tilingMode

The mode controlling tiling settings, which Must be set to one of the four MODE_* values. The default is MODE_COPY_FROM_METADATA.

Subclasses that do not writing tiles may ignore this value.

See Also
MODE_DISABLED, MODE_EXPLICIT, MODE_COPY_FROM_METADATA, MODE_DEFAULT, setTilingMode, getTilingMode
tilingSetback to summary
protected boolean tilingSet

A boolean that is true if tiling parameters have been specified.

Subclasses that do not support writing tiles may ignore this value.

Constructor Detail

ImageWriteParamback to summary
protected ImageWriteParam()

Constructs an empty ImageWriteParam. It is up to the subclass to set up the instance variables properly.

ImageWriteParamback to summary
public ImageWriteParam(Locale locale)

Constructs an ImageWriteParam set to use a given Locale.

Parameters
locale:Locale

a Locale to be used to localize compression type names and quality descriptions, or null.

Method Detail

canOffsetTilesback to summary
public boolean canOffsetTiles()

Returns true if the writer can perform tiling with non-zero grid offsets while writing. If this method returns false, then setTiling will throw an UnsupportedOperationException if the grid offset arguments are not both zero. If canWriteTiles returns false, this method will return false as well.

Returns:boolean

true if the writer supports non-zero tile offsets.

See Also
canWriteTiles(), setTiling(int, int, int, int)
canWriteCompressedback to summary
public boolean canWriteCompressed()

Returns true if this writer supports compression.

Returns:boolean

true if the writer supports compression.

canWriteProgressiveback to summary
public boolean canWriteProgressive()

Returns true if the writer can write out images as a series of passes of progressively increasing quality.

Returns:boolean

true if the writer supports progressive encoding.

See Also
setProgressiveMode, getProgressiveMode
canWriteTilesback to summary
public boolean canWriteTiles()

Returns true if the writer can perform tiling while writing. If this method returns false, then setTiling will throw an UnsupportedOperationException.

Returns:boolean

true if the writer supports tiling.

See Also
canOffsetTiles(), setTiling(int, int, int, int)
clonePreferredTileSizesback to summary
private static Dimension[] clonePreferredTileSizes(Dimension[] sizes)
getBitRateback to summary
public float getBitRate(float quality)

Returns a float indicating an estimate of the number of bits of output data for each bit of input image data at the given quality level. The value will typically lie between 0 and 1, with smaller values indicating more compression. A special value of -1.0F is used to indicate that no estimate is available.

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks that compression is supported and the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() is null or getCompressionType() is non-null, and quality is within bounds, it returns -1.0.

Parameters
quality:float

the quality setting whose bit rate is to be queried.

Returns:float

an estimate of the compressed bit rate, or -1.0F if no estimate is available.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
IllegalArgumentException:
if quality is not between 0 and 1, inclusive.
getCompressionModeback to summary
public int getCompressionMode()

Returns the current compression mode, if compression is supported.

Returns:int

the current compression mode.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
See Also
setCompressionMode
getCompressionQualityback to summary
public float getCompressionQuality()

Returns the current compression quality setting.

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks that compression is supported and that the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() is null or getCompressionType() is non-null, it returns the value of the compressionQuality instance variable.

Returns:float

the current compression quality setting.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
See Also
setCompressionQuality
getCompressionQualityDescriptionsback to summary
public String[] getCompressionQualityDescriptions()

Returns an array of Strings that may be used along with getCompressionQualityValues as part of a user interface for setting or displaying the compression quality level. The String with index i provides a description of the range of quality levels between getCompressionQualityValues[i] and getCompressionQualityValues[i + 1]. Note that the length of the array returned from getCompressionQualityValues will always be one greater than that returned from getCompressionQualityDescriptions.

As an example, the strings "Good", "Better", and "Best" could be associated with the ranges [0, .33), [.33, .66), and [.66, 1.0]. In this case, getCompressionQualityDescriptions would return { "Good", "Better", "Best" } and getCompressionQualityValues would return { 0.0F, .33F, .66F, 1.0F }.

If no descriptions are available, null is returned. If null is returned from getCompressionQualityValues, this method must also return null.

The descriptions should be localized for the Locale returned by getLocale, if it is non-null.

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks that compression is supported and that the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() is null or getCompressionType() is non-null, it returns null.

Returns:String[]

an array of Strings containing localized descriptions of the compression quality levels.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
See Also
getCompressionQualityValues
getCompressionQualityValuesback to summary
public float[] getCompressionQualityValues()

Returns an array of floats that may be used along with getCompressionQualityDescriptions as part of a user interface for setting or displaying the compression quality level. See getCompressionQualityDescriptions for more information.

If no descriptions are available, null is returned. If null is returned from getCompressionQualityDescriptions, this method must also return null.

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks that compression is supported and that the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() is null or getCompressionType() is non-null, it returns null.

Returns:float[]

an array of floats indicating the boundaries between the compression quality levels as described by the Strings from getCompressionQualityDescriptions.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
See Also
getCompressionQualityDescriptions
getCompressionTypeback to summary
public String getCompressionType()

Returns the currently set compression type, or null if none has been set. The type is returned as a String from among those returned by getCompressionTypes. If no compression type has been set, null is returned.

The default implementation checks whether compression is supported and the compression mode is MODE_EXPLICIT. If so, it returns the value of the compressionType instance variable.

Returns:String

the current compression type as a String, or null if no type is set.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
if the compression mode is not MODE_EXPLICIT.
See Also
setCompressionType
getCompressionTypesback to summary
public String[] getCompressionTypes()

Returns a list of available compression types, as an array or Strings, or null if a compression type may not be chosen using these interfaces. The array returned is a copy.

If the writer only offers a single, mandatory form of compression, it is not necessary to provide any named compression types. Named compression types should only be used where the user is able to make a meaningful choice between different schemes.

The default implementation checks if compression is supported and throws an UnsupportedOperationException if not. Otherwise, it returns a clone of the compressionTypes instance variable if it is non-null, or else returns null.

Returns:String[]

an array of Strings containing the (non-localized) names of available compression types, or null.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
getLocaleback to summary
public Locale getLocale()

Returns the currently set Locale, or null if only a default Locale is supported.

Returns:Locale

the current Locale, or null.

getLocalizedCompressionTypeNameback to summary
public String getLocalizedCompressionTypeName()

Returns a localized version of the name of the current compression type, using the Locale returned by getLocale.

The default implementation checks whether compression is supported and the compression mode is MODE_EXPLICIT. If so, if compressionType is non-null the value of getCompressionType is returned as a convenience.

Returns:String

a String containing a localized version of the name of the current compression type.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if no compression type is set.
getPreferredTileSizesback to summary
public Dimension[] getPreferredTileSizes()

Returns an array of Dimensions indicating the legal size ranges for tiles as they will be encoded in the output file or stream. The returned array is a copy.

The information is returned as a set of pairs; the first element of a pair contains an (inclusive) minimum width and height, and the second element contains an (inclusive) maximum width and height. Together, each pair defines a valid range of sizes. To specify a fixed size, use the same width and height for both elements. To specify an arbitrary range, a value of null is used in place of an actual array of Dimensions.

If no array is specified on the constructor, but tiling is allowed, then this method returns null.

Returns:Dimension[]

an array of Dimensions with an even length of at least two, or null.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
getProgressiveModeback to summary
public int getProgressiveMode()

Returns the current mode for writing the stream in a progressive manner.

Returns:int

the current mode for progressive encoding.

Exceptions
UnsupportedOperationException:
if the writer does not support progressive encoding.
See Also
setProgressiveMode
getTileGridXOffsetback to summary
public int getTileGridXOffset()

Returns the horizontal tile grid offset of an image as it will be written to the output stream. If tiling parameters have not been set, an IllegalStateException is thrown.

Returns:int

the tile grid X offset to be used for encoding.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
IllegalStateException:
  • if the tiling mode is not MODE_EXPLICIT.
  • if the tiling parameters have not been set.
See Also
setTiling(int, int, int, int), getTileGridYOffset()
getTileGridYOffsetback to summary
public int getTileGridYOffset()

Returns the vertical tile grid offset of an image as it will be written to the output stream. If tiling parameters have not been set, an IllegalStateException is thrown.

Returns:int

the tile grid Y offset to be used for encoding.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
IllegalStateException:
  • if the tiling mode is not MODE_EXPLICIT.
  • if the tiling parameters have not been set.
See Also
setTiling(int, int, int, int), getTileGridXOffset()
getTileHeightback to summary
public int getTileHeight()

Returns the height of each tile in an image as it will be written to the output stream. If tiling parameters have not been set, an IllegalStateException is thrown.

Returns:int

the tile height to be used for encoding.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
IllegalStateException:
  • if the tiling mode is not MODE_EXPLICIT.
  • if the tiling parameters have not been set.
See Also
setTiling(int, int, int, int), getTileWidth()
getTileWidthback to summary
public int getTileWidth()

Returns the width of each tile in an image as it will be written to the output stream. If tiling parameters have not been set, an IllegalStateException is thrown.

Returns:int

the tile width to be used for encoding.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
IllegalStateException:
  • if the tiling mode is not MODE_EXPLICIT.
  • if the tiling parameters have not been set.
See Also
setTiling(int, int, int, int), getTileHeight()
getTilingModeback to summary
public int getTilingMode()

Returns the current tiling mode, if tiling is supported. Otherwise throws an UnsupportedOperationException.

Returns:int

the current tiling mode.

Exceptions
UnsupportedOperationException:
if canWriteTiles returns false.
See Also
setTilingMode
isCompressionLosslessback to summary
public boolean isCompressionLossless()

Returns true if the current compression type provides lossless compression. If a plug-in provides only one mandatory compression type, then this method may be called without calling setCompressionType first.

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks whether compression is supported and the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() is null or getCompressionType() is non-null true is returned as a convenience.

Returns:boolean

true if the current compression type is lossless.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
setCompressionModeback to summary
public void setCompressionMode(int mode)

Specifies whether compression is to be performed, and if so how compression parameters are to be determined. The mode argument must be one of the four modes, interpreted as follows:

  • MODE_DISABLED - If the mode is set to MODE_DISABLED, methods that query or modify the compression type or parameters will throw an IllegalStateException (if compression is normally supported by the plug-in). Some writers, such as JPEG, do not normally offer uncompressed output. In this case, attempting to set the mode to MODE_DISABLED will throw an UnsupportedOperationException and the mode will not be changed.
  • MODE_EXPLICIT - Compress using the compression type and quality settings specified in this ImageWriteParam. Any previously set compression parameters are discarded.
  • MODE_COPY_FROM_METADATA - Use whatever compression parameters are specified in metadata objects passed in to the writer.
  • MODE_DEFAULT - Use default compression parameters.

The default is MODE_COPY_FROM_METADATA.

Parameters
mode:int

The mode for setting compression in the output stream.

Exceptions
UnsupportedOperationException:
if the writer does not support compression, or does not support the requested mode.
IllegalArgumentException:
if mode is not one of the modes listed above.
See Also
getCompressionMode
setCompressionQualityback to summary
public void setCompressionQuality(float quality)

Sets the compression quality to a value between 0 and 1. Only a single compression quality setting is supported by default; writers can provide extended versions of ImageWriteParam that offer more control. For lossy compression schemes, the compression quality should control the tradeoff between file size and image quality (for example, by choosing quantization tables when writing JPEG images). For lossless schemes, the compression quality may be used to control the tradeoff between file size and time taken to perform the compression (for example, by optimizing row filters and setting the ZLIB compression level when writing PNG images).

A compression quality setting of 0.0 is most generically interpreted as "high compression is important," while a setting of 1.0 is most generically interpreted as "high image quality is important."

If there are multiple compression types but none has been set, an IllegalStateException is thrown.

The default implementation checks that compression is supported, and that the compression mode is MODE_EXPLICIT. If so, if getCompressionTypes() returns null or compressionType is non-null it sets the compressionQuality instance variable.

Parameters
quality:float

a float between 0 and 1 indicating the desired quality level.

Exceptions
UnsupportedOperationException:
if the writer does not support compression.
IllegalStateException:
  • if the compression mode is not MODE_EXPLICIT.
  • if the set of legal compression types is non-null and the current compression type is null.
IllegalArgumentException:
if quality is not between 0 and 1, inclusive.
See Also
getCompressionQuality
setCompressionTypeback to summary
public void setCompressionType(String compressionType)

Sets the compression type to one of the values indicated by getCompressionTypes. If a value of null is passed in, any previous setting is removed.

The default implementation checks whether compression is supported and the compression mode is MODE_EXPLICIT. If so, it calls getCompressionTypes and checks if compressionType is one of the legal values. If it is, the compressionType instance variable is set. If compressionType is null, the instance variable is set without performing any checking.

Parameters
compressionType:String

one of the Strings returned by getCompressionTypes, or null to remove any previous setting.

Exceptions
UnsupportedOperationException:
  • if the writer does not support compression.
  • if there are no settable compression types.
IllegalStateException:
if the compression mode is not MODE_EXPLICIT.
IllegalArgumentException:
if compressionType is non-null but is not one of the values returned by getCompressionTypes.
See Also
getCompressionTypes, getCompressionType, unsetCompression
setProgressiveModeback to summary
public void setProgressiveMode(int mode)

Specifies that the writer is to write the image out in a progressive mode such that the stream will contain a series of scans of increasing quality. If progressive encoding is not supported, an UnsupportedOperationException will be thrown.

The mode argument determines how the progression parameters are chosen, and must be either MODE_DISABLED, MODE_COPY_FROM_METADATA, or MODE_DEFAULT. Otherwise an IllegalArgumentException is thrown.

The modes are interpreted as follows:

  • MODE_DISABLED - No progression. Use this to turn off progression.
  • MODE_COPY_FROM_METADATA - The output image will use whatever progression parameters are found in the metadata objects passed into the writer.
  • MODE_DEFAULT - The image will be written progressively, with parameters chosen by the writer.

The default is MODE_COPY_FROM_METADATA.

Parameters
mode:int

The mode for setting progression in the output stream.

Exceptions
UnsupportedOperationException:
if the writer does not support progressive encoding.
IllegalArgumentException:
if mode is not one of the modes listed above.
See Also
getProgressiveMode
setTilingback to summary
public void setTiling(int tileWidth, int tileHeight, int tileGridXOffset, int tileGridYOffset)

Specifies that the image should be tiled in the output stream. The tileWidth and tileHeight parameters specify the width and height of the tiles in the file. If the tile width or height is greater than the width or height of the image, the image is not tiled in that dimension.

If canOffsetTiles returns false, then the tileGridXOffset and tileGridYOffset parameters must be zero.

Parameters
tileWidth:int

the width of each tile.

tileHeight:int

the height of each tile.

tileGridXOffset:int

the horizontal offset of the tile grid.

tileGridYOffset:int

the vertical offset of the tile grid.

Exceptions
UnsupportedOperationException:
  • if the plug-in does not support tiling.
  • if the plug-in does not support grid offsets, and the grid offsets are not both zero.
IllegalStateException:
if the tiling mode is not MODE_EXPLICIT.
IllegalArgumentException:
  • if the tile size is not within one of the allowable ranges returned by getPreferredTileSizes.
  • if tileWidth or tileHeight is less than or equal to 0.
See Also
canWriteTiles, canOffsetTiles, getTileWidth(), getTileHeight(), getTileGridXOffset(), getTileGridYOffset()
setTilingModeback to summary
public void setTilingMode(int mode)

Determines whether the image will be tiled in the output stream and, if it will, how the tiling parameters will be determined. The modes are interpreted as follows:

  • MODE_DISABLED - The image will not be tiled. setTiling will throw an IllegalStateException.
  • MODE_DEFAULT - The image will be tiled using default parameters. setTiling will throw an IllegalStateException.
  • MODE_EXPLICIT - The image will be tiled according to parameters given in the setTiling method. Any previously set tiling parameters are discarded.
  • MODE_COPY_FROM_METADATA - The image will conform to the metadata object passed in to a write. setTiling will throw an IllegalStateException.
Parameters
mode:int

The mode to use for tiling.

Exceptions
UnsupportedOperationException:
if canWriteTiles returns false.
IllegalArgumentException:
if mode is not one of the modes listed above.
See Also
setTiling, getTilingMode
unsetCompressionback to summary
public void unsetCompression()

Removes any previous compression type and quality settings.

The default implementation sets the instance variable compressionType to null, and the instance variable compressionQuality to 1.0F.

Exceptions
UnsupportedOperationException:
if the plug-in does not support compression.
IllegalStateException:
if the compression mode is not MODE_EXPLICIT.
See Also
setCompressionType, setCompressionQuality
unsetTilingback to summary
public void unsetTiling()

Removes any previous tile grid parameters specified by calls to setTiling.

The default implementation sets the instance variables tileWidth, tileHeight, tileGridXOffset, and tileGridYOffset to 0.

Exceptions
UnsupportedOperationException:
if the plug-in does not support tiling.
IllegalStateException:
if the tiling mode is not MODE_EXPLICIT.
See Also
setTiling(int, int, int, int)