/*
* $RCSfile: MeanDescriptor.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:57:39 $
* $State: Exp $
*/
package com.lightcrafts.mediax.jai.operator;
import java.awt.RenderingHints;
import java.awt.image.RenderedImage;
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.ROI;
import com.lightcrafts.mediax.jai.RenderedOp;
import com.lightcrafts.mediax.jai.registry.RenderedRegistryMode;
/**
* An <code>OperationDescriptor</code> describing the "Mean" operation.
*
* <p> The Mean operation scans a specific region of a rendered image
* and computes the mean pixel value for each band within that region
* of the image. The image data pass through this operation unchanged.
*
* <p>The region-wise mean pixel value for each band may be
* retrieved by calling the <code>getProperty</code> method on this
* operation with "mean" as the property name. The return value has
* type <code>double[#bands]</code>.
*
* <p>The region of interest (ROI) does not have to be a rectangle.
* It may be <code>null</code>, in which case the entire image is
* scanned to find the image-wise mean pixel value for each band.
*
* <p>The set of pixels scanned may be further reduced by
* specifying the "xPeriod" and "yPeriod" parameters that represent
* the sampling rate along each axis. These variables may not be
* less than 1. However, they may be <code>null</code>, in which
* case the sampling rate is set to 1; that is, every pixel in the
* ROI is processed.
*
* <p><table border=1>
* <caption>Resource List</caption>
* <tr><th>Name</th> <th>Value</th></tr>
* <tr><td>GlobalName</td> <td>Mean</td></tr>
* <tr><td>LocalName</td> <td>Mean</td></tr>
* <tr><td>Vendor</td> <td>com.lightcrafts.media.jai</td></tr>
* <tr><td>Description</td> <td>Calculates the region-wise mean pixel value
* for each band of an image.</td></tr>
* <tr><td>DocURL</td> <td>http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/MeanDescriptor.html</td></tr>
* <tr><td>Version</td> <td>1.0</td></tr>
* <tr><td>arg0Desc</td> <td>The region of the image to scan.</td></tr>
* <tr><td>arg1Desc</td> <td>The horizontal sampling rate,
* may not be less than 1.</td></tr>
* <tr><td>arg2Desc</td> <td>The vertical sampling rate,
* may not be less than 1.</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>roi</td> <td>com.lightcrafts.mediax.jai.ROI</td>
* <td>null</td>
* <tr><td>xPeriod</td> <td>java.lang.Integer</td>
* <td>1</td>
* <tr><td>yPeriod</td> <td>java.lang.Integer</td>
* <td>1</td>
* </table></p>
*
* @see com.lightcrafts.mediax.jai.ROI
* @see com.lightcrafts.mediax.jai.OperationDescriptor
*/
public class MeanDescriptor extends OperationDescriptorImpl {
/**
* The resource strings that provide the general documentation
* and specify the parameter list for this operation.
*/
private static final String[][] resources = {
{"GlobalName", "Mean"},
{"LocalName", "Mean"},
{"Vendor", "com.lightcrafts.media.jai"},
{"Description", JaiI18N.getString("MeanDescriptor0")},
{"DocURL", "http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/MeanDescriptor.html"},
{"Version", JaiI18N.getString("DescriptorVersion")},
{"arg0Desc", JaiI18N.getString("MeanDescriptor1")},
{"arg1Desc", JaiI18N.getString("MeanDescriptor2")},
{"arg2Desc", JaiI18N.getString("MeanDescriptor3")}
};
/** The parameter name list for this operation. */
private static final String[] paramNames = {
"roi", "xPeriod", "yPeriod"
};
/** The parameter class list for this operation. */
private static final Class[] paramClasses = {
com.lightcrafts.mediax.jai.ROI.class,
java.lang.Integer.class,
java.lang.Integer.class
};
/** The parameter default value list for this operation. */
private static final Object[] paramDefaults = {
null, new Integer(1), new Integer(1)
};
/** Constructor. */
public MeanDescriptor() {
super(resources, 1, paramClasses, paramNames, paramDefaults);
}
/**
* Returns the minimum legal value of a specified numeric parameter
* for this operation.
*/
public Number getParamMinValue(int index) {
if (index == 0) {
return null;
} else if (index == 1 || index == 2) {
return new Integer(1);
} else {
throw new ArrayIndexOutOfBoundsException();
}
}
/**
* Calculates the image-wise mean pixel value for each band of an image.
*
* <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 source0 <code>RenderedImage</code> source 0.
* @param roi The region of the image to scan.
* May be <code>null</code>.
* @param xPeriod The horizontal sampling rate, may not be less than 1.
* May be <code>null</code>.
* @param yPeriod The vertical sampling rate, may not be less than 1.
* 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>source0</code> is <code>null</code>.
*/
public static RenderedOp create(RenderedImage source0,
ROI roi,
Integer xPeriod,
Integer yPeriod,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("Mean",
RenderedRegistryMode.MODE_NAME);
pb.setSource("source0", source0);
pb.setParameter("roi", roi);
pb.setParameter("xPeriod", xPeriod);
pb.setParameter("yPeriod", yPeriod);
return JAI.create("Mean", pb, hints);
}
}