javax.media.jai.operator
Class PNGDescriptor

java.lang.Object
  javax.media.jai.OperationDescriptorImpl
      javax.media.jai.operator.PNGDescriptor

All Implemented Interfaces:

OperationDescriptor, RegistryElementDescriptor, Serializable

public class PNGDescriptor

extends OperationDescriptorImpl

An OperationDescriptor describing the "PNG" operation.

The "PNG" operation reads a standard PNG version 1.1 input stream. The PNG (Portable Network Graphics) specification may be found at http://www.cdrom.com/pub/png/spec.

The "PNG" operation implements the entire PNG specification, but provides access only to the final, high-resolution version of interlaced images.

The second parameter contains an instance of PNGDecodeParam to be used during the decoding. It may be set to null in order to perform default decoding, or equivalently may be omitted.

The documentation for PNGDecodeParam describes the possible output formats of PNG images after decoding.

The classes in the com.sun.media.jai.codec package are not a committed part of the JAI API. Future releases of JAI will make use of new classes in their place. This class will change accordingly.

Resource List

Name	Value
GlobalName	PNG
LocalName	PNG
Vendor	com.sun.media.jai
Description	Reads an image from a PNG stream.
DocURL	http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PNGDescriptor.html
Version	1.0
arg0Desc	The SeekableStream to read from.
arg1Desc	The PNGDecodeParam to use.

Parameter List

Name	Class Type	Default Value
stream	com.sun.media.jai.codec.SeekableStream	NO_PARAMETER_DEFAULT
param	com.sun.media.jai.codec.PNGDecodeParam	null

Properties

Property Name	Class	Comment
file_type	String	"PNG v. 1.0"
background_color	java.awt.Color	The suggested background color.
significant_bits	int[]	The number of significant bits stored in the file.
bit_depth	Integer	The bit depth of the file
color_type	String	One of "Grayscale", "Truecolor", "Index", "Grayscale with alpha" or "Truecolor with alpha"
interlace_method	String	"None" or "Adam7"
white_point_x	Float	The CIE X coordinate of the white point, if known.
white_point_y	Float	The CIE Y coordinate of the white point, if known.
red_x	Float	The CIE X coordinate of the red primary, if known.
red_y	Float	The CIE Y coordinate of the red primary, if known.
green_x	Float	The CIE X coordinate of the green primary, if known.
green_y	Float	The CIE Y coordinate of the green primary, if known.
blue_x	Float	The CIE X coordinate of the blue primary, if known.
blue_y	Float	The CIE Y coordinate of the blue primary, if known.
gamma	Float	The image gamma, if known.
x_pixels_per_unit	Integer	The number of horizontal pixels per unit.
y_pixels_per_unit	Integer	The number of vertical pixels per unit.
pixel_aspect_ratio	Float	The width of a pixel divided by its height.
pixel_units	String	"Meters" or null
timestamp	java.util.Date	The creation or modification time of the image.
text:*	String	The value of a tEXt chunk.
ztext:*	String	The value of a zTXt chunk (not yet implemented).
chunk:*	byte[]	The contents of any non-standard chunks.

See Also:

PNGDecodeParam, SeekableStream, OperationDescriptor, Serialized Form

Field Summary

Fields inherited from class javax.media.jai.OperationDescriptorImpl

sourceNames, supportedModes

Fields inherited from interface javax.media.jai.OperationDescriptor

NO_PARAMETER_DEFAULT

Constructor Summary

PNGDescriptor()
Constructor.

Method Summary

static RenderedOp

create(SeekableStream stream, PNGDecodeParam param, RenderingHints hints) Reads a standard JFIF (PNG) file.

Methods inherited from class javax.media.jai.OperationDescriptorImpl

arePropertiesSupported, getDefaultSourceClass, getDestClass, getDestClass, getInvalidRegion, getName, getNumParameters, getNumSources, getParamClasses, getParamDefaults, getParamDefaultValue, getParameterListDescriptor, getParamMaxValue, getParamMinValue, getParamNames, getPropertyGenerators, getPropertyGenerators, getRenderableDestClass, getRenderableSourceClasses, getResourceBundle, getResources, getSourceClasses, getSourceClasses, getSourceNames, getSupportedModes, isImmediate, isModeSupported, isRenderableSupported, isRenderedSupported, makeDefaultSourceClassList, validateArguments, validateArguments, validateParameters, validateParameters, validateRenderableArguments, validateRenderableSources, validateSources, validateSources

Methods inherited from class java.lang.Object

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

Constructor Detail

PNGDescriptor

public PNGDescriptor()

Constructor.

Method Detail

create

public static RenderedOp create(SeekableStream stream,
                                PNGDecodeParam param,
                                RenderingHints hints)

Reads a standard JFIF (PNG) file.

Creates a ParameterBlockJAI from all supplied arguments except hints and invokes JAI.create(String,ParameterBlock,RenderingHints).

Parameters:

stream - The SeekableStream to read from.

param - The PNGDecodeParam to use. May be null.

hints - The RenderingHints to use. May be null.

Returns:

The RenderedOp destination.

Throws:

IllegalArgumentException - if stream is null.

See Also:

JAI, ParameterBlockJAI, RenderedOp