com.sun.media.imageio.plugins.bmp

Class BMPImageWriteParam

public class BMPImageWriteParam extends ImageWriteParam

A subclass of ImageWriteParam for encoding images in the BMP format.

This class allows for the specification of various parameters while writing a BMP format image file. By default, the data layout is bottom-up, such that the pixels are stored in bottom-up order, the first scanline being stored last.

The particular compression scheme to be used can be specified by using the setCompressionType() method with the appropriate type string. The compression scheme specified will be honored if and only if it is compatible with the type of image being written. If the specified compression scheme is not compatible with the type of image being written then the IOException will be thrown by the BMP image writer. If the compression type is not set explicitly then getCompressionType() will return null. In this case the BMP image writer will select a compression type that supports encoding of the given image without loss of the color resolution.

The compression type strings and the image type(s) each supports are listed in the following table:

**Compression Types**
Type String	Description	Image Types
BI_RGB	Uncompressed RLE	<= 8-bits/sample
BI_RLE8	8-bit Run Length Encoding	<= 8-bits/sample
BI_RLE4	4-bit Run Length Encoding	<= 4-bits/sample
BI_BITFIELDS	Packed data	16 or 32 bits/sample
BI_JPEG	JPEG encoded	grayscale or RGB image

When BI_BITFIELDS is used, if the image encoded has a DirectColorModel, the bit mask in the color model will be written into the stream. Otherwise, only 5-5-5 16-bit image or 8-8-8 32-bit images are supported.

Field Summary
static int	VERSION_2 Constant for BMP version 2.
static int	VERSION_3 Constant for BMP version 3.
static int	VERSION_4 Constant for BMP version 4.
static int	VERSION_5 Constant for BMP version 5.

Constructor Summary
	BMPImageWriteParam(Locale locale) Constructs a `BMPImageWriteParam` set to use a given `Locale` and with default values for all parameters.
	BMPImageWriteParam() Constructs an `BMPImageWriteParam` object with default values for all parameters and a `null` `Locale`.

Method Summary
int	getVersion() Returns the BMP version to be used.
boolean	isTopDown() Returns the value of the `topDown` parameter.
void	setCompressionType(String compressionType) Sets the compression type to one of the values indicated by `getCompressionTypes`.
void	setTopDown(boolean topDown) If set, the data will be written out in a top-down manner, the first scanline being written first.

Field Detail

VERSION_2

public static final int VERSION_2

Deprecated:

Constant for BMP version 2.

VERSION_3

public static final int VERSION_3

Deprecated:

Constant for BMP version 3.

VERSION_4

public static final int VERSION_4

Deprecated:

Constant for BMP version 4.

VERSION_5

public static final int VERSION_5

Deprecated:

Constant for BMP version 5.

Constructor Detail

BMPImageWriteParam

public BMPImageWriteParam(Locale locale)

Constructs a BMPImageWriteParam set to use a given Locale and with default values for all parameters.

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

BMPImageWriteParam

public BMPImageWriteParam()

Constructs an BMPImageWriteParam object with default values for all parameters and a null Locale.

Method Detail

getVersion

public int getVersion()

Deprecated:

Returns the BMP version to be used. The default is VERSION_3.

Returns: the BMP version number.

isTopDown

public boolean isTopDown()

Returns the value of the topDown parameter. The default is false.

Returns: whether the data are written in top-down order.

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 method first invokes javax.imageio.ImageWriteParam.#setCompressionType(String) setCompressionType() with the supplied value of compressionType. Next, if isTopDown returns true and the value of compressionType is incompatible with top-down order, BMPImageWriteParam is invoked with parameter topDown set to false. The image will then be written in bottom-up order with the specified compressionType.

Parameters: compressionType one of the Strings 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.

setTopDown

public void setTopDown(boolean topDown)

If set, the data will be written out in a top-down manner, the first scanline being written first. Any compression other than BI_RGB or BI_BITFIELDS is incompatible with the data being written in top-down order. Setting the topDown argument to true will be honored only when the compression type at the time of writing the image is one of the two mentioned above. Otherwise, the topDown setting will be ignored.

Parameters: topDown whether the data are written in top-down order.