/*
* $RCSfile: PNGDescriptor.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:57:42 $
* $State: Exp $
*/
package com.lightcrafts.mediax.jai.operator;
import com.lightcrafts.media.jai.codec.PNGDecodeParam;
import com.lightcrafts.media.jai.codec.SeekableStream;
import java.awt.RenderingHints;
import java.awt.image.renderable.ParameterBlock;
import com.lightcrafts.mediax.jai.JAI;
import com.lightcrafts.mediax.jai.OperationDescriptorImpl;
import com.lightcrafts.mediax.jai.ParameterBlockJAI;
import com.lightcrafts.mediax.jai.RenderedOp;
import com.lightcrafts.mediax.jai.registry.RenderedRegistryMode;
/**
* An <code>OperationDescriptor</code> describing the "PNG" operation.
*
* <p> The "PNG" operation reads a standard PNG version 1.1 input stream.
* The PNG (Portable Network Graphics) specification may be
* found at <a href="http://www.cdrom.com/pub/png/spec">
* <code>http://www.cdrom.com/pub/png/spec</code></a>.
*
* <p> The "PNG" operation implements the entire PNG specification,
* but provides access only to the final, high-resolution version of
* interlaced images.
*
* <p> The second parameter contains an instance of
* <code>PNGDecodeParam</code> to be used during the decoding.
* It may be set to <code>null</code> in order to perform default
* decoding, or equivalently may be omitted.
*
* <p> The documentation for <code>PNGDecodeParam</code> describes the
* possible output formats of PNG images after decoding.
*
* <p><b> The classes in the <code>com.lightcrafts.media.jai.codec</code>
* 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.</b>
*
* <p><table border=1>
* <caption>Resource List</caption>
* <tr><th>Name</th> <th>Value</th></tr>
* <tr><td>GlobalName</td> <td>PNG</td></tr>
* <tr><td>LocalName</td> <td>PNG</td></tr>
* <tr><td>Vendor</td> <td>com.lightcrafts.media.jai</td></tr>
* <tr><td>Description</td> <td>Reads an image from a PNG stream.</td></tr>
* <tr><td>DocURL</td> <td>http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PNGDescriptor.html</td></tr>
* <tr><td>Version</td> <td>1.0</td></tr>
* <tr><td>arg0Desc</td> <td>The SeekableStream to read from.</td></tr>
* <tr><td>arg1Desc</td> <td>The PNGDecodeParam to use.</td></tr>
* </table></p>
*
* <p><table border=1>
* <caption>Parameter List</caption>
* <tr><th>Name</th> <th>Class Type</th>
* <th>Default Value</th></tr>
* <tr><td>stream</td> <td>com.lightcrafts.media.jai.codec.SeekableStream</td>
* <td>NO_PARAMETER_DEFAULT</td>
* <tr><td>param</td> <td>com.lightcrafts.media.jai.codec.PNGDecodeParam</td>
* <td>null</td>
* </table></p>
*
* <p><table border=1>
* <caption>Properties</caption>
* <tr><th>Property Name</th> <th>Class</th> <th>Comment</th></tr>
*
* <tr><td>file_type</td> <td>String</td>
* <td>"PNG v. 1.0"</td> </tr>
* <tr><td>background_color</td> <td>java.awt.Color</td>
* <td>The suggested background color.</td> </tr>
* <tr><td>significant_bits</td> <td>int[]</td>
* <td>The number of significant bits stored in the file.</td> </tr>
* <tr><td>bit_depth</td> <td>Integer</td>
* <td>The bit depth of the file</td> </tr>
* <tr><td>color_type</td> <td>String</td>
* <td>One of "Grayscale", "Truecolor", "Index",
* "Grayscale with alpha" or "Truecolor with alpha"</td> </tr>
* <tr><td>interlace_method</td> <td>String</td>
* <td>"None" or "Adam7"</td> </tr>
* <tr><td>white_point_x</td> <td>Float</td>
* <td>The CIE X coordinate of the white point, if known.</td> </tr>
* <tr><td>white_point_y</td> <td>Float</td>
* <td>The CIE Y coordinate of the white point, if known.</td> </tr>
* <tr><td>red_x</td> <td>Float</td>
* <td>The CIE X coordinate of the red primary, if known.</td> </tr>
* <tr><td>red_y</td> <td>Float</td>
* <td>The CIE Y coordinate of the red primary, if known.</td> </tr>
* <tr><td>green_x</td> <td>Float</td>
* <td>The CIE X coordinate of the green primary, if known.</td> </tr>
* <tr><td>green_y</td> <td>Float</td>
* <td>The CIE Y coordinate of the green primary, if known.</td> </tr>
* <tr><td>blue_x</td> <td>Float</td>
* <td>The CIE X coordinate of the blue primary, if known.</td> </tr>
* <tr><td>blue_y</td> <td>Float</td>
* <td>The CIE Y coordinate of the blue primary, if known.</td> </tr>
* <tr><td>gamma</td> <td>Float</td>
* <td>The image gamma, if known.</td> </tr>
* <tr><td>x_pixels_per_unit</td> <td>Integer</td>
* <td>The number of horizontal pixels per unit.</td> </tr>
* <tr><td>y_pixels_per_unit</td> <td>Integer</td>
* <td>The number of vertical pixels per unit.</td> </tr>
* <tr><td>pixel_aspect_ratio</td> <td>Float</td>
* <td>The width of a pixel divided by its height.</td> </tr>
* <tr><td>pixel_units</td> <td>String</td>
* <td>"Meters" or <code>null</code></td> </tr>
* <tr><td>timestamp</td> <td>java.util.Date</td>
* <td>The creation or modification time of the image.</td> </tr>
* <tr><td>text:*</td> <td>String</td>
* <td>The value of a tEXt chunk.</td> </tr>
* <tr><td>ztext:*</td> <td>String</td>
* <td>The value of a zTXt chunk (not yet implemented).</td> </tr>
* <tr><td>chunk:*</td> <td>byte[]</td>
* <td>The contents of any non-standard chunks.</td> </tr>
* </table></p>
*
* @see com.lightcrafts.media.jai.codec.PNGDecodeParam
* @see com.lightcrafts.media.jai.codec.SeekableStream
* @see com.lightcrafts.mediax.jai.OperationDescriptor
*/
public class PNGDescriptor extends OperationDescriptorImpl {
/**
* The resource strings that provide the general documentation and
* specify the parameter list for the "PNG" operation.
*/
private static final String[][] resources = {
{"GlobalName", "PNG"},
{"LocalName", "PNG"},
{"Vendor", "com.lightcrafts.media.jai"},
{"Description", JaiI18N.getString("PNGDescriptor0")},
{"DocURL", "http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PNGDescriptor.html"},
{"Version", JaiI18N.getString("DescriptorVersion")},
{"arg0Desc", JaiI18N.getString("PNGDescriptor1")},
{"arg1Desc", JaiI18N.getString("PNGDescriptor2")},
};
/** The parameter names for the "PNG" operation. */
private static final String[] paramNames = {
"stream", "param"
};
/** The parameter class types for the "PNG" operation. */
private static final Class[] paramClasses = {
com.lightcrafts.media.jai.codec.SeekableStream.class,
com.lightcrafts.media.jai.codec.PNGDecodeParam.class
};
/** The parameter default values for the "PNG" operation. */
private static final Object[] paramDefaults = {
NO_PARAMETER_DEFAULT, null
};
/** Constructor. */
public PNGDescriptor() {
super(resources, 0, paramClasses, paramNames, paramDefaults);
}
/**
* Reads a standard JFIF (PNG) file.
*
* <p>Creates a <code>ParameterBlockJAI</code> from all
* supplied arguments except <code>hints</code> and invokes
* {@link JAI#create(String,ParameterBlock,RenderingHints)}.
*
* @see JAI
* @see ParameterBlockJAI
* @see RenderedOp
*
* @param stream The SeekableStream to read from.
* @param param The PNGDecodeParam to use.
* May be <code>null</code>.
* @param hints The <code>RenderingHints</code> to use.
* May be <code>null</code>.
* @return The <code>RenderedOp</code> destination.
* @throws IllegalArgumentException if <code>stream</code> is <code>null</code>.
*/
public static RenderedOp create(SeekableStream stream,
PNGDecodeParam param,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("PNG",
RenderedRegistryMode.MODE_NAME);
pb.setParameter("stream", stream);
pb.setParameter("param", param);
return JAI.create("PNG", pb, hints);
}
}