Module java.desktop
Package javax.imageio

# Class ImageWriteParam

java.lang.Object
javax.imageio.IIOParam
javax.imageio.ImageWriteParam

Direct Known Subclasses:
  `BMPImageWriteParam`, `JPEGImageWriteParam`

public class ImageWriteParam extends IIOParam
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

Fields
Modifier and Type
Field
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 `String`s 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`.
`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.
`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.
`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.
`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.

### Fields declared in class javax.imageio.IIOParam

`controller, defaultController, destinationOffset, destinationType, sourceBands, sourceRegion, sourceXSubsampling, sourceYSubsampling, subsamplingXOffset, subsamplingYOffset`

## Constructor Summary

Constructors
Modifier
Constructor
Description
`protected`
`ImageWriteParam()`
Constructs an empty `ImageWriteParam`.
``
`ImageWriteParam(Locale locale)`
Constructs an `ImageWriteParam` set to use a given `Locale`.

## Method Summary

Modifier and Type
Method
Description
`boolean`
`canOffsetTiles()`
Returns `true` if the writer can perform tiling with non-zero grid offsets while writing.
`boolean`
`canWriteCompressed()`
Returns `true` if this writer supports compression.
`boolean`
`canWriteProgressive()`
Returns `true` if the writer can write out images as a series of passes of progressively increasing quality.
`boolean`
`canWriteTiles()`
Returns `true` if the writer can perform tiling while writing.
`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.
`int`
`getCompressionMode()`
Returns the current compression mode, if compression is supported.
`float`
`getCompressionQuality()`
Returns the current compression quality setting.
`String[]`
`getCompressionQualityDescriptions()`
Returns an array of `String`s that may be used along with `getCompressionQualityValues` as part of a user interface for setting or displaying the compression quality level.
`float[]`
`getCompressionQualityValues()`
Returns an array of `float`s that may be used along with `getCompressionQualityDescriptions` as part of a user interface for setting or displaying the compression quality level.
`String`
`getCompressionType()`
Returns the currently set compression type, or `null` if none has been set.
`String[]`
`getCompressionTypes()`
Returns a list of available compression types, as an array or `String`s, or `null` if a compression type may not be chosen using these interfaces.
`Locale`
`getLocale()`
Returns the currently set `Locale`, or `null` if only a default `Locale` is supported.
`String`
`getLocalizedCompressionTypeName()`
Returns a localized version of the name of the current compression type, using the `Locale` returned by `getLocale`.
`Dimension[]`
`getPreferredTileSizes()`
Returns an array of `Dimension`s indicating the legal size ranges for tiles as they will be encoded in the output file or stream.
`int`
`getProgressiveMode()`
Returns the current mode for writing the stream in a progressive manner.
`int`
`getTileGridXOffset()`
Returns the horizontal tile grid offset of an image as it will be written to the output stream.
`int`
`getTileGridYOffset()`
Returns the vertical tile grid offset of an image as it will be written to the output stream.
`int`
`getTileHeight()`
Returns the height of each tile in an image as it will be written to the output stream.
`int`
`getTileWidth()`
Returns the width of each tile in an image as it will be written to the output stream.
`int`
`getTilingMode()`
Returns the current tiling mode, if tiling is supported.
`boolean`
`isCompressionLossless()`
Returns `true` if the current compression type provides lossless compression.
`void`
`setCompressionMode(int mode)`
Specifies whether compression is to be performed, and if so how compression parameters are to be determined.
`void`
`setCompressionQuality(float quality)`
Sets the compression quality to a value between `0` and `1`.
`void`
`setCompressionType(String compressionType)`
Sets the compression type to one of the values indicated by `getCompressionTypes`.
`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.
`void`
`setTiling(int tileWidth, int tileHeight, int tileGridXOffset, int tileGridYOffset)`
Specifies that the image should be tiled in the output stream.
`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.
`void`
`unsetCompression()`
Removes any previous compression type and quality settings.
`void`
`unsetTiling()`
Removes any previous tile grid parameters specified by calls to `setTiling`.

### Methods declared in class javax.imageio.IIOParam

`activateController, getController, getDefaultController, getDestinationOffset, getDestinationType, getSourceBands, getSourceRegion, getSourceXSubsampling, getSourceYSubsampling, getSubsamplingXOffset, getSubsamplingYOffset, hasController, setController, setDestinationOffset, setDestinationType, setSourceBands, setSourceRegion, setSourceSubsampling`

### Methods declared in class java.lang.Object

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

## Field Details

### MODE_DISABLED

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(int)`
  - `getProgressiveMode()`
  - `setTilingMode(int)`
  - `getTilingMode()`
  - `setCompressionMode(int)`
  - `getCompressionMode()`
  - Constant Field Values

### MODE_DEFAULT

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(int)`
  - `getProgressiveMode()`
  - `setTilingMode(int)`
  - `getTilingMode()`
  - `setCompressionMode(int)`
  - `getCompressionMode()`
  - Constant Field Values

### MODE_EXPLICIT

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(int)`
  - `getProgressiveMode()`
  - `setTilingMode(int)`
  - `getTilingMode()`
  - `setCompressionMode(int)`
  - `getCompressionMode()`
  - Constant Field Values

### MODE_COPY_FROM_METADATA

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(int)`
  - `getProgressiveMode()`
  - `setTilingMode(int)`
  - `getTilingMode()`
  - `setCompressionMode(int)`
  - `getCompressionMode()`
  - Constant Field Values

### canWriteTiles

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`.

### tilingMode

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(int)`
  - `getTilingMode()`

### preferredTileSizes

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()`

### tilingSet

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.

### tileWidth

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.

### tileHeight

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.

### canOffsetTiles

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`.

### tileGridXOffset

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.

### tileGridYOffset

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.

### canWriteProgressive

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`.

### progressiveMode

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(int)`
  - `getProgressiveMode()`

### canWriteCompressed

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`.

### compressionMode

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(int)`
  - `getCompressionMode()`

### compressionTypes

protected String[] compressionTypes
An array of `String`s containing the names of the available compression types. Subclasses must set the value manually.

Subclasses that do not support compression may ignore this value.

### compressionType

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.

### compressionQuality

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.

### locale

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.

## Constructor Details

### ImageWriteParam

protected ImageWriteParam()
Constructs an empty `ImageWriteParam`. It is up to the subclass to set up the instance variables properly.

### ImageWriteParam

public ImageWriteParam(Locale locale)
Constructs an `ImageWriteParam` set to use a given `Locale`.

Parameters:
  `locale` - a `Locale` to be used to localize compression type names and quality descriptions, or `null`.

## Method Details

### getLocale

public Locale getLocale()
Returns the currently set `Locale`, or `null` if only a default `Locale` is supported.

Returns:
  the current `Locale`, or `null`.

### canWriteTiles

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:
  `true` if the writer supports tiling.
See Also:
  - `canOffsetTiles()`
  - `setTiling(int, int, int, int)`

### canOffsetTiles

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:
  `true` if the writer supports non-zero tile offsets.
See Also:
  - `canWriteTiles()`
  - `setTiling(int, int, int, int)`

### setTilingMode

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` - The mode to use for tiling.
Throws:
  `UnsupportedOperationException` - if `canWriteTiles` returns `false`.
  `IllegalArgumentException` - if `mode` is not one of the modes listed above.
See Also:
  - `setTiling(int, int, int, int)`
  - `getTilingMode()`

### getTilingMode

public int getTilingMode()
Returns the current tiling mode, if tiling is supported. Otherwise throws an `UnsupportedOperationException`.

Returns:
  the current tiling mode.
Throws:
  `UnsupportedOperationException` - if `canWriteTiles` returns `false`.
See Also:
  - `setTilingMode(int)`

### getPreferredTileSizes

public Dimension[] getPreferredTileSizes()
Returns an array of `Dimension`s 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 `Dimension`s.

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

Returns:
  an array of `Dimension`s with an even length of at least two, or `null`.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.

### setTiling

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` - the width of each tile.
  `tileHeight` - the height of each tile.
  `tileGridXOffset` - the horizontal offset of the tile grid.
  `tileGridYOffset` - the vertical offset of the tile grid.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.
  `IllegalStateException` - if the tiling mode is not `MODE_EXPLICIT`.
  `UnsupportedOperationException` - if the plug-in does not support grid offsets, and the grid offsets are not both zero.
  `IllegalArgumentException` - if the tile size is not within one of the allowable ranges returned by `getPreferredTileSizes`.
  `IllegalArgumentException` - if `tileWidth` or `tileHeight` is less than or equal to 0.
See Also:
  - `canWriteTiles`
  - `canOffsetTiles`
  - `getTileWidth()`
  - `getTileHeight()`
  - `getTileGridXOffset()`
  - `getTileGridYOffset()`

### unsetTiling

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`.

Throws:
  `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)`

### getTileWidth

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:
  the tile width to be used for encoding.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.
  `IllegalStateException` - if the tiling mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the tiling parameters have not been set.
See Also:
  - `setTiling(int, int, int, int)`
  - `getTileHeight()`

### getTileHeight

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:
  the tile height to be used for encoding.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.
  `IllegalStateException` - if the tiling mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the tiling parameters have not been set.
See Also:
  - `setTiling(int, int, int, int)`
  - `getTileWidth()`

### getTileGridXOffset

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:
  the tile grid X offset to be used for encoding.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.
  `IllegalStateException` - if the tiling mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the tiling parameters have not been set.
See Also:
  - `setTiling(int, int, int, int)`
  - `getTileGridYOffset()`

### getTileGridYOffset

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:
  the tile grid Y offset to be used for encoding.
Throws:
  `UnsupportedOperationException` - if the plug-in does not support tiling.
  `IllegalStateException` - if the tiling mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the tiling parameters have not been set.
See Also:
  - `setTiling(int, int, int, int)`
  - `getTileGridXOffset()`

### canWriteProgressive

public boolean canWriteProgressive()
Returns `true` if the writer can write out images as a series of passes of progressively increasing quality.

Returns:
  `true` if the writer supports progressive encoding.
See Also:
  - `setProgressiveMode(int)`
  - `getProgressiveMode()`

### setProgressiveMode

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` - The mode for setting progression in the output stream.
Throws:
  `UnsupportedOperationException` - if the writer does not support progressive encoding.
  `IllegalArgumentException` - if `mode` is not one of the modes listed above.
See Also:
  - `getProgressiveMode()`

### getProgressiveMode

public int getProgressiveMode()
Returns the current mode for writing the stream in a progressive manner.

Returns:
  the current mode for progressive encoding.
Throws:
  `UnsupportedOperationException` - if the writer does not support progressive encoding.
See Also:
  - `setProgressiveMode(int)`

### canWriteCompressed

public boolean canWriteCompressed()
Returns `true` if this writer supports compression.

Returns:
  `true` if the writer supports compression.

### setCompressionMode

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` - The mode for setting compression in the output stream.
Throws:
  `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()`

### getCompressionMode

public int getCompressionMode()
Returns the current compression mode, if compression is supported.

Returns:
  the current compression mode.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
See Also:
  - `setCompressionMode(int)`

### getCompressionTypes

public String[] getCompressionTypes()
Returns a list of available compression types, as an array or `String`s, 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:
  an array of `String`s containing the (non-localized) names of available compression types, or `null`.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.

### setCompressionType

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` - one of the `String`s returned by `getCompressionTypes`, or `null` to remove any previous setting.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `UnsupportedOperationException` - if there are no settable compression types.
  `IllegalArgumentException` - if `compressionType` is non-`null` but is not one of the values returned by `getCompressionTypes`.
See Also:
  - `getCompressionTypes()`
  - `getCompressionType()`
  - `unsetCompression()`

### getCompressionType

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:
  the current compression type as a `String`, or `null` if no type is set.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
See Also:
  - `setCompressionType(java.lang.String)`

### unsetCompression

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`.

Throws:
  `UnsupportedOperationException` - if the plug-in does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
See Also:
  - `setCompressionType(java.lang.String)`
  - `setCompressionQuality(float)`

### getLocalizedCompressionTypeName

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:
  a `String` containing a localized version of the name of the current compression type.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if no compression type is set.

### isCompressionLossless

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:
  `true` if the current compression type is lossless.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the set of legal compression types is non-`null` and the current compression type is `null`.

### setCompressionQuality

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` - a `float` between `0` and `1` indicating the desired quality level.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - 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()`

### getCompressionQuality

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:
  the current compression quality setting.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the set of legal compression types is non-`null` and the current compression type is `null`.
See Also:
  - `setCompressionQuality(float)`

### getBitRate

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` - the quality setting whose bit rate is to be queried.
Returns:
  an estimate of the compressed bit rate, or `-1.0F` if no estimate is available.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - 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.

### getCompressionQualityDescriptions

public String[] getCompressionQualityDescriptions()
Returns an array of `String`s 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:
  an array of `String`s containing localized descriptions of the compression quality levels.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the set of legal compression types is non-`null` and the current compression type is `null`.
See Also:
  - `getCompressionQualityValues()`

### getCompressionQualityValues

public float[] getCompressionQualityValues()
Returns an array of `float`s 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:
  an array of `float`s indicating the boundaries between the compression quality levels as described by the `String`s from `getCompressionQualityDescriptions`.
Throws:
  `UnsupportedOperationException` - if the writer does not support compression.
  `IllegalStateException` - if the compression mode is not `MODE_EXPLICIT`.
  `IllegalStateException` - if the set of legal compression types is non-`null` and the current compression type is `null`.
See Also:
  - `getCompressionQualityDescriptions()`