libjava/java/awt/image/Kernel.java

   1 /* Kernel.java -- Java class for an image processing kernel
   2    Copyright (C) 2004, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.image;
  40
  41 /**
  42  * Kernel represents an image processing kernel.  It gets used to hold
  43  * convolution filters among other purposes.  It stores an array of float
  44  * values representing a 2-dimensional array in row-major order.
  45  *
  46  * @author Jerry Quinn (jlquinn@optonline.net)
  47  * @version 1.0
  48  */
  49 public class Kernel implements Cloneable
  50 {
  51   private final int width;
  52   private final int height;
  53   private final float[] data;
  54
  55   /**
  56    * Creates a new <code>Kernel</code> instance.
  57    *
  58    * @param width The 2D width of data.
  59    * @param height The 2D height of data.
  60    * @param data The source data array.
  61    * @exception IllegalArgumentException if width * height < data.length.
  62    */
  63   public Kernel(int width, int height, float[] data)
  64     throws IllegalArgumentException
  65   {
  66     this.width = width;
  67     this.height = height;
  68     if (data.length < width * height || width < 0 || height < 0)
  69       throw new IllegalArgumentException();
  70     this.data = new float[width * height];
  71     System.arraycopy(data, 0, this.data, 0, width * height);
  72   }
  73
  74   /**
  75    * Return the X origin: (width - 1) / 2
  76    */
  77   public final int getXOrigin()
  78   {
  79     return (width - 1) / 2;
  80   }
  81
  82   /**
  83    * Return the Y origin: (height - 1) / 2
  84    */
  85   public final int getYOrigin()
  86   {
  87     return (height - 1) / 2;
  88   }
  89
  90   /**
  91    * @return The kernel width.
  92    */
  93   public final int getWidth()
  94   {
  95     return width;
  96   }
  97
  98   /**
  99    * @return The kernel height.
 100    */
 101   public final int getHeight()
 102   {
 103     return height;
 104   }
 105
 106   /**
 107    * Return the kernel data.
 108    *
 109    * If data is null, allocates a new array and returns it.  Otherwise, the
 110    * kernel values are copied into data.
 111    *
 112    * @param data Array to copy values into, or null.
 113    * @return The array with copied values.
 114    * @exception IllegalArgumentException if data != null and too small.
 115    */
 116   public final float[] getKernelData(float[] data)
 117     throws IllegalArgumentException
 118   {
 119     if (data == null)
 120       return (float[])this.data.clone();
 121
 122     if (data.length < this.data.length)
 123       throw new IllegalArgumentException();
 124
 125     System.arraycopy(this.data, 0, data, 0, this.data.length);
 126     return data;
 127   }
 128
 129   /**
 130    * @return a clone of this Kernel.
 131    */
 132   public Object clone()
 133   {
 134     try
 135       {
 136         return super.clone();
 137       }
 138     catch (CloneNotSupportedException e)
 139       {
 140         throw (Error) new InternalError().initCause(e); // Impossible
 141       }
 142   }
 143 }