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Class DCT


public class DCT
extends Object

Discrete Cosine Transformations.

Field Summary

double[][]
c
Cosine matrix
double[][]
cT
Transformed cosine matrix

Constructor Summary

DCT()
The basic constructor.

Method Summary

static double
C(int u)
Figure A.3.3 IDCT, Cu Cv on A-5 of the ISO DIS 10918-1.
float[][]
fast_fdct(float[][] input)
double[][]
fast_idct(double[][] input)
fast_idct - Figure A.3.3 IDCT (informative) on A-5 of the ISO DIS 10918-1.
double[][]
idj_fast_fdct(input[][] )
static float[][]
slow_fdct(float[][] value)
static double[][]
slow_idct(double[][] matrix)
slow_idct - Figure A.3.3 IDCT (informative) on A-5 of the ISO DIS 10918-1.

Methods inherited from class java.lang.Object

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

Field Details

c

public double[][] c
Cosine matrix

cT

public double[][] cT
Transformed cosine matrix

Constructor Details

DCT

public DCT()
The basic constructor. Object is special, because it has no superclass, so there is no call to super().

Method Details

C

public static double C(int u)
Figure A.3.3 IDCT, Cu Cv on A-5 of the ISO DIS 10918-1. Requirements and Guidelines.
Parameters:
u -
Returns:

fast_fdct

public float[][] fast_fdct(float[][] input)

fast_idct

public double[][] fast_idct(double[][] input)
fast_idct - Figure A.3.3 IDCT (informative) on A-5 of the ISO DIS 10918-1. Requires and Guidelines. This is a fast IDCT, it much more effecient and only inaccurate at about 1/1000th of a percent of values analyzed. Cannot be static because initMatrix must run before any fast_idct values can be computed.
Parameters:
input -
Returns:

idj_fast_fdct

public double[][] idj_fast_fdct(input[][] )

slow_fdct

public static float[][] slow_fdct(float[][] value)

slow_idct

public static double[][] slow_idct(double[][] matrix)
slow_idct - Figure A.3.3 IDCT (informative) on A-5 of the ISO DIS 10918-1. Requirements and Guidelines. This is a slow IDCT, there are better algorithms to use, it's fairly expensive with processor speed.
Parameters:
matrix -
Returns:

DCT.java -- Copyright (C) 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.