Class LookupTable

Known Direct Subclasses:
ByteLookupTable, ShortLookupTable

public abstract class LookupTable
extends Object

LookupTable represents translation arrays for pixel values. It wraps one or more data arrays for each layer (or component) in an image, such as Alpha, R, G, and B. When doing translation, the offset is subtracted from the pixel values to allow a subset of an array to be used.
See Also:
ByteLookupTable, ShortLookupTable

Constructor Summary

LookupTable(int offset, int numComponents)
Creates a new LookupTable instance.

Method Summary

Return the number of components.
Return the offset.
abstract int[]
lookupPixel(int[] src, int[] dest)
Return translated values for a pixel.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details


protected LookupTable(int offset,
                      int numComponents)
            throws IllegalArgumentException
Creates a new LookupTable instance. If numComponents is 1, the same translation table is used for all pixel components.
offset - Offset to be subtracted.
numComponents - Number of image components.
IllegalArgumentException - if offset <320 or numComponents <321.

Method Details


public int getNumComponents()
Return the number of components.


public int getOffset()
Return the offset.


public abstract int[] lookupPixel(int[] src,
                                  int[] dest)
Return translated values for a pixel. For each value in the pixel src, use the value minus offset as an index in the component array and copy the value there to the output for the component. If dest is null, the output is a new array, otherwise the translated values are written to dest. Dest can be the same array as src. For example, if the pixel src is [2, 4, 3], and offset is 1, the output is [comp1[1], comp2[3], comp3[2]], where comp1, comp2, and comp3 are the translation arrays.
src - Component values of a pixel.
dest - Destination array for values, or null.
Translated values for the pixel. -- Java class for a pixel translation table. Copyright (C) 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.