/*
* $RCSfile: SubtractConstDescriptor.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:57:45 $
* $State: Exp $
*/
package com.lightcrafts.mediax.jai.operator;
import java.awt.RenderingHints;
import java.awt.image.RenderedImage;
import java.awt.image.renderable.ParameterBlock;
import java.awt.image.renderable.RenderableImage;
import com.lightcrafts.mediax.jai.JAI;
import com.lightcrafts.mediax.jai.OperationDescriptorImpl;
import com.lightcrafts.mediax.jai.ParameterBlockJAI;
import com.lightcrafts.mediax.jai.RenderableOp;
import com.lightcrafts.mediax.jai.RenderedOp;
import com.lightcrafts.mediax.jai.registry.RenderableRegistryMode;
import com.lightcrafts.mediax.jai.registry.RenderedRegistryMode;
/**
* An <code>OperationDescriptor</code> describing the "SubtractConst"
* operation.
*
* <p> The SubtractConst operation takes one rendered or renderable
* source image and an array of double constants, and subtracts a
* constant from every pixel of its corresponding band of the
* source. If the number of constants supplied is less than the number
* of bands of the destination, then the constant from entry 0 is
* applied to all the bands. Otherwise, a constant from a different
* entry is applied to each band.
*
* <p> By default, the destination image bounds, data type, and number
* of bands are the same as the source image. If the result of the
* operation underflows/overflows the minimum/maximum value supported
* by the destination data type, then it will be clamped to the
* minimum/maximum value respectively.
*
* <p> The destination pixel values are defined by the pseudocode:
* <pre>
* if (constants.length < dstNumBands) {
* dst[x][y][b] = src[x][y][b] - constants[0];
* } else {
* dst[x][y][b] = src[x][y][b] - constants[b];
* }
* </pre>
*
* <p><table border=1>
* <caption>Resource List</caption>
* <tr><th>Name</th> <th>Value</th></tr>
* <tr><td>GlobalName</td> <td>SubtractConst</td></tr>
* <tr><td>LocalName</td> <td>SubtractConst</td></tr>
* <tr><td>Vendor</td> <td>com.lightcrafts.media.jai</td></tr>
* <tr><td>Description</td> <td>Subtracts constants from an
* image.<td></tr>
* <tr><td>DocURL</td> <td>http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/SubtractConstDescriptor.html</td></tr>
* <tr><td>Version</td> <td>1.0</td></tr>
* <tr><td>arg0Desc</td> <td>The constants to be subtracted.</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>constants</td> <td>double[]</td>
* <td>NO_PARAMETER_DEFAULT</td>
* </table></p>
*
* @see com.lightcrafts.mediax.jai.OperationDescriptor
*/
public class SubtractConstDescriptor extends OperationDescriptorImpl {
/**
* The resource strings that provide the general documentation
* and specify the parameter list for this operation.
*/
private static final String[][] resources = {
{"GlobalName", "SubtractConst"},
{"LocalName", "SubtractConst"},
{"Vendor", "com.lightcrafts.media.jai"},
{"Description", JaiI18N.getString("SubtractConstDescriptor0")},
{"DocURL", "http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/SubtractConstDescriptor.html"},
{"Version", JaiI18N.getString("DescriptorVersion")},
{"arg0Desc", JaiI18N.getString("SubtractConstDescriptor1")}
};
/**
* The parameter class list for this operation.
* The number of constants provided should be either 1, in which case
* this same constant is applied to all the source bands; or the same
* number as the source bands, in which case one contant is applied
* to each band.
*/
private static final Class[] paramClasses = {
double[].class
};
/** The parameter name list for this operation. */
private static final String[] paramNames = {
"constants"
};
/** The parameter default value list for this operation. */
private static final Object[] paramDefaults = {
NO_PARAMETER_DEFAULT
};
/** Constructor. */
public SubtractConstDescriptor() {
super(resources, 1, paramClasses, paramNames, paramDefaults);
}
/** Returns <code>true</code> since renderable operation is supported. */
public boolean isRenderableSupported() {
return true;
}
/**
* Validates the input parameter.
*
* <p> In addition to the standard checks performed by the
* superclass method, this method checks that the length of the
* "constants" array is at least 1.
*/
protected boolean validateParameters(ParameterBlock args,
StringBuffer message) {
if (!super.validateParameters(args, message)) {
return false;
}
int length = ((double[])args.getObjectParameter(0)).length;
if (length < 1) {
message.append(getName() + " " +
JaiI18N.getString("SubtractConstDescriptor2"));
return false;
}
return true;
}
/**
* Subtracts constants from 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 constants The constants to be subtracted.
* @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>.
* @throws IllegalArgumentException if <code>constants</code> is <code>null</code>.
*/
public static RenderedOp create(RenderedImage source0,
double[] constants,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("SubtractConst",
RenderedRegistryMode.MODE_NAME);
pb.setSource("source0", source0);
pb.setParameter("constants", constants);
return JAI.create("SubtractConst", pb, hints);
}
/**
* Subtracts constants from an image.
*
* <p>Creates a <code>ParameterBlockJAI</code> from all
* supplied arguments except <code>hints</code> and invokes
* {@link JAI#createRenderable(String,ParameterBlock,RenderingHints)}.
*
* @see JAI
* @see ParameterBlockJAI
* @see RenderableOp
*
* @param source0 <code>RenderableImage</code> source 0.
* @param constants The constants to be subtracted.
* @param hints The <code>RenderingHints</code> to use.
* May be <code>null</code>.
* @return The <code>RenderableOp</code> destination.
* @throws IllegalArgumentException if <code>source0</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>constants</code> is <code>null</code>.
*/
public static RenderableOp createRenderable(RenderableImage source0,
double[] constants,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("SubtractConst",
RenderableRegistryMode.MODE_NAME);
pb.setSource("source0", source0);
pb.setParameter("constants", constants);
return JAI.createRenderable("SubtractConst", pb, hints);
}
}