/*
* $RCSfile: PiecewiseDescriptor.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:57:43 $
* $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 "Piecewise" operation.
*
* <p> The "Piecewise" operation performs a piecewise linear mapping of the
* pixel values of an image. The piecewise linear mapping is described by a
* set of breakpoints which are provided as an array of the form
* <pre>float breakPoints[N][2][numBreakPoints]</pre> where the value of
* <i>N</i> may be either unity or the number of bands in the source image.
* If <i>N</i> is unity then the same set of breakpoints will be applied to
* all bands in the image. The abscissas of the supplied breakpoints must
* be monotonically increasing.
*
* <p> The pixel values of the destination image are defined by the pseudocode:
*
* <pre>
* if (src[x][y][b] < breakPoints[b][0][0]) {
* dst[x][y][b] = breakPoints[b][1][0]);
* } else if (src[x][y][b] > breakPoints[b][0][numBreakPoints-1]) {
* dst[x][y][b] = breakPoints[b][1][numBreakPoints-1]);
* } else {
* int i = 0;
* while(breakPoints[b][0][i+1] < src[x][y][b]) {
* i++;
* }
* dst[x][y][b] = breakPoints[b][1][i] +
* (src[x][y][b] - breakPoints[b][0][i])*
* (breakPoints[b][1][i+1] - breakPoints[b][1][i])/
* (breakPoints[b][0][i+1] - breakPoints[b][0][i]);
* }
* </pre>
*
* <p><table border=1>
* <caption>Resource List</caption>
* <tr><th>Name</th> <th>Value</th></tr>
* <tr><td>GlobalName</td> <td>Piecewise</td></tr>
* <tr><td>LocalName</td> <td>Piecewise</td></tr>
* <tr><td>Vendor</td> <td>com.lightcrafts.media.jai</td></tr>
* <tr><td>Description</td> <td>Applies a piecewise pixel value mapping.</td></tr>
* <tr><td>DocURL</td> <td>http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PiecewiseDescriptor.html</td></tr>
* <tr><td>Version</td> <td>1.0</td></tr>
* <tr><td>arg0Desc</td> <td>The breakpoint array.</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>breakPoints</td> <td>float[][][]</td>
* <td>identity mapping on [0, 255]</td>
* </table></p>
*
* @see java.awt.image.DataBuffer
* @see com.lightcrafts.mediax.jai.ImageLayout
* @see com.lightcrafts.mediax.jai.OperationDescriptor
*/
public class PiecewiseDescriptor extends OperationDescriptorImpl {
/**
* The resource strings that provide the general documentation
* and specify the parameter list for this operation.
*/
private static final String[][] resources = {
{"GlobalName", "Piecewise"},
{"LocalName", "Piecewise"},
{"Vendor", "com.lightcrafts.media.jai"},
{"Description", JaiI18N.getString("PiecewiseDescriptor0")},
{"DocURL", "http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PiecewiseDescriptor.html"},
{"Version", JaiI18N.getString("DescriptorVersion")},
{"arg0Desc", "The breakpoint array."}
};
/** The parameter class list for this operation. */
private static final Class[] paramClasses = {
float[][][].class
};
/** The parameter name list for this operation. */
private static final String[] paramNames = {
"breakPoints"
};
/** The parameter default value list for this operation. */
private static final Object[] paramDefaults = {
new float[][][]{{{0.0f, 255.0f}, {0.0f, 255.0f}}}
};
private static final String[] supportedModes = {
"rendered",
"renderable"
};
/** Constructor. */
public PiecewiseDescriptor() {
super(resources, supportedModes, 1,
paramNames, paramClasses, paramDefaults, null);
}
/**
* Validates the input source and parameter.
*
* <p> In addition to the standard checks performed by the
* superclass method, this method checks that the number of bands
* in "breakPoints" is either 1 or the number of bands in the
* source image, the second breakpoint array dimension is 2,
* the third dimension is the same for abscissas and ordinates,
* and that the absicssas are monotonically increasing.
*/
public boolean validateArguments(String modeName,
ParameterBlock args,
StringBuffer msg) {
if (!super.validateArguments(modeName, args, msg)) {
return false;
}
if (!modeName.equalsIgnoreCase("rendered"))
return true;
// Get the source and the breakpoint array.
RenderedImage src = args.getRenderedSource(0);
float[][][] breakPoints =
(float[][][])args.getObjectParameter(0);
// Ensure that the number of breakpoint bands is either 1 or
// the number of bands in the source image, the second
// breakpoint array dimension is 2, the third dimension is
// the same for abscissas and ordinates, and that the absicssas
// are monotonically increasing.
if (breakPoints.length != 1 &&
breakPoints.length != src.getSampleModel().getNumBands()) {
// Number of breakpoints not 1 nor numBands.
msg.append(getName() + " " +
JaiI18N.getString("PiecewiseDescriptor1"));
return false;
} else {
int numBands = breakPoints.length;
for (int b = 0; b < numBands; b++) {
if (breakPoints[b].length != 2) {
// Second breakpoint dimension not 2.
msg.append(getName() + " " +
JaiI18N.getString("PiecewiseDescriptor2"));
return false;
} else if (breakPoints[b][0].length !=
breakPoints[b][1].length) {
// Differing numbers of abscissas and ordinates.
msg.append(getName() + " " +
JaiI18N.getString("PiecewiseDescriptor3"));
return false;
}
}
for (int b = 0; b < numBands; b++) {
int count = breakPoints[b][0].length - 1;
float[] x = breakPoints[b][0];
for (int i = 0; i < count; i++) {
if (x[i] >= x[i+1]) {
// Abscissas not monotonically increasing.
msg.append(getName() + " " +
JaiI18N.getString("PiecewiseDescriptor4"));
return false;
}
}
}
}
return true;
}
/**
* Applies a piecewise pixel value mapping.
*
* <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 breakPoints The breakpoint array.
* 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,
float[][][] breakPoints,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("Piecewise",
RenderedRegistryMode.MODE_NAME);
pb.setSource("source0", source0);
pb.setParameter("breakPoints", breakPoints);
return JAI.create("Piecewise", pb, hints);
}
/**
* Applies a piecewise pixel value mapping.
*
* <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 breakPoints The breakpoint array.
* May be <code>null</code>.
* @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>.
*/
public static RenderableOp createRenderable(RenderableImage source0,
float[][][] breakPoints,
RenderingHints hints) {
ParameterBlockJAI pb =
new ParameterBlockJAI("Piecewise",
RenderableRegistryMode.MODE_NAME);
pb.setSource("source0", source0);
pb.setParameter("breakPoints", breakPoints);
return JAI.createRenderable("Piecewise", pb, hints);
}
}