/* Randomly change values in a double matrix to 0.0 or 255.0.

 @Copyright (c) 2004-2005 The Regents of the University of California.
 All rights reserved.

 Permission is hereby granted, without written agreement and without
 license or royalty fees, to use, copy, modify, and distribute this
 software and its documentation for any purpose, provided that the
 above copyright notice and the following two paragraphs appear in all
 copies of this software.

 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 ENHANCEMENTS, OR MODIFICATIONS.

 PT_COPYRIGHT_VERSION_2
 COPYRIGHTENDKEY



 */
package ptolemy.actor.lib.jai;

import ptolemy.actor.lib.Transformer;
import ptolemy.data.DoubleMatrixToken;
import ptolemy.data.DoubleToken;
import ptolemy.data.expr.Parameter;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.Attribute;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;

//////////////////////////////////////////////////////////////////////////
//// SaltAndPepper

/** Randomly change values in a double matrix to 0.0 or 255.0.

 <p>This actor reads in a double matrix and then randomly changes
 some of the matrix elements to 0.0 or to 255.0.  Some of the elements
 remain unchanged.  If the double matrix represents an image, then
 the image would appear to have Salt and Pepper scattered on it.

 @author James Yeh, Contributor: Christopher Hylands Brooks
 @version $Id$
 @since Ptolemy II 4.0
 @Pt.ProposedRating Red (cxh)
 @Pt.AcceptedRating Red (cxh)
 */
public class SaltAndPepper extends Transformer {
    /** Construct an actor with the given container and name.
     *  @param container The container.
     *  @param name The name of this actor.
     *  @exception IllegalActionException If the actor cannot be contained
     *   by the proposed container.
     *  @exception NameDuplicationException If the container already has an
     *   actor with this name.
     */
    public SaltAndPepper(CompositeEntity container, String name)
            throws IllegalActionException, NameDuplicationException {
        super(container, name);
        input.setTypeEquals(BaseType.DOUBLE_MATRIX);
        output.setTypeEquals(BaseType.DOUBLE_MATRIX);

        probability = new Parameter(this, "probability",
                new DoubleToken("0.1F"));
    }

    ///////////////////////////////////////////////////////////////////
    ////                     ports and parameters                  ////

    /** The probability that a pixel will be turned black or white.
     *  This parameter contains a double between 0.0 and 1.0, the
     *  initial default value is 0.1.  With the initial default value
     *  of 0.1, then there is a 5% chance a pixel will be turned
     *  white, a 5% chance that the pixel will be turned black
     *  and a 90% chance that the pixel will remain unchanged.
     */
    public Parameter probability;

    ///////////////////////////////////////////////////////////////////
    ////                         public methods                    ////

    /** React to a change in the value of an attribute.
     *  @param attribute The attribute whose type changed.
     *  @exception IllegalActionException Not thrown in this base class.
     */
    public void attributeChanged(Attribute attribute)
            throws IllegalActionException {
        if (attribute == probability) {
            _probability = ((DoubleToken) probability.getToken()).doubleValue();
        } else {
            super.attributeChanged(attribute);
        }
    }

    /** Read in a matrix of doubles, randomly change some matrix
     *  elements to either 0.0 or 255.0 and send the results to the
     *  output.
     *  @exception IllegalActionException If there is a problem reading
     *  or writing a token.
     */
    public void fire() throws IllegalActionException {
        super.fire();

        DoubleMatrixToken doubleMatrixToken = (DoubleMatrixToken) input.get(0);
        double[][] data = doubleMatrixToken.doubleMatrix();
        int width = doubleMatrixToken.getRowCount();
        int height = doubleMatrixToken.getColumnCount();

        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                double value = Math.random();

                if (value < _probability) {
                    if (value < (_probability / 2)) {
                        data[i][j] = 0.0F;
                    } else {
                        data[i][j] = 255.0F;
                    }
                }
            }
        }

        output.send(0, new DoubleMatrixToken(data));
    }

    ///////////////////////////////////////////////////////////////////
    ////                         private variables                 ////
    private double _probability;
}