edu.emory.mathcs.jtransforms.dct

Class DoubleDCT_2D

java.lang.Object

edu.emory.mathcs.jtransforms.dct.DoubleDCT_2D

public class DoubleDCT_2D
extends java.lang.Object

Computes 2D Discrete Cosine Transform (DCT) of double precision data. The sizes of both dimensions can be arbitrary numbers. This is a parallel implementation of split-radix and mixed-radix algorithms optimized for SMP systems.

Part of the code is derived from General Purpose FFT Package written by Takuya Ooura (http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html)

Constructor Summary

Constructors

Constructor and Description
DoubleDCT_2D(int rows, int columns) Creates new instance of DoubleDCT_2D.

Method Summary

Modifier and Type	Method and Description
void	forward(double[][] a, boolean scale) Computes 2D forward DCT (DCT-II) leaving the result in a.
void	forward(double[] a, boolean scale) Computes 2D forward DCT (DCT-II) leaving the result in a.
void	inverse(double[][] a, boolean scale) Computes 2D inverse DCT (DCT-III) leaving the result in a.
void	inverse(double[] a, boolean scale) Computes 2D inverse DCT (DCT-III) leaving the result in a.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DoubleDCT_2D

public DoubleDCT_2D(int rows,
                    int columns)

Creates new instance of DoubleDCT_2D.

Parameters:

rows - number of rows

columns - number of columns

Method Detail

forward

public void forward(double[] a,
                    boolean scale)

Computes 2D forward DCT (DCT-II) leaving the result in a. The data is stored in 1D array in row-major order.

Parameters:

a - data to transform

scale - if true then scaling is performed

forward

public void forward(double[][] a,
                    boolean scale)

Computes 2D forward DCT (DCT-II) leaving the result in a. The data is stored in 2D array.

Parameters:

a - data to transform

scale - if true then scaling is performed

inverse

public void inverse(double[] a,
                    boolean scale)

Computes 2D inverse DCT (DCT-III) leaving the result in a. The data is stored in 1D array in row-major order.

Parameters:

a - data to transform

scale - if true then scaling is performed

inverse

public void inverse(double[][] a,
                    boolean scale)

Computes 2D inverse DCT (DCT-III) leaving the result in a. The data is stored in 2D array.

Parameters:

a - data to transform

scale - if true then scaling is performed