be.tarsos.dsp.wavelet

Class HaarWaveletTransform

java.lang.Object

be.tarsos.dsp.wavelet.HaarWaveletTransform

public class HaarWaveletTransform
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
HaarWaveletTransform()
HaarWaveletTransform(boolean preserveEnergy)

Method Summary

Modifier and Type	Method and Description
void	inverseTransform(float[] data) Does an in-place inverse HaarWavelet Wavelet Transform.
static boolean	isPowerOfTwo(int number) Checks if the number is a power of two.
static int	log2(int bits) A quick and simple way to calculate log2 of integers.
static int	pow2(int power) A quick way to calculate the power of two (2^power), by using bit shifts.
void	transform(float[] s) Does an in-place HaarWavelet wavelet transform.

Methods inherited from class java.lang.Object

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

Constructor Detail

HaarWaveletTransform

public HaarWaveletTransform(boolean preserveEnergy)

HaarWaveletTransform

public HaarWaveletTransform()

Method Detail

transform

public void transform(float[] s)

Does an in-place HaarWavelet wavelet transform. The length of data needs to be a power of two. It is based on the algorithm found in "Wavelets Made Easy" by Yves Nivergelt, page 24.

Parameters:

s - The data to transform.

inverseTransform

public void inverseTransform(float[] data)

Does an in-place inverse HaarWavelet Wavelet Transform. The data needs to be a power of two. It is based on the algorithm found in "Wavelets Made Easy" by Yves Nivergelt, page 29.

Parameters:

data - The data to transform.

isPowerOfTwo

public static boolean isPowerOfTwo(int number)

Checks if the number is a power of two. For performance it uses bit shift operators. e.g. 4 in binary format is "0000 0000 0000 0000 0000 0000 0000 0100"; and -4 is "1111 1111 1111 1111 1111 1111 1111 1100"; and 4&-4 will be "0000 0000 0000 0000 0000 0000 0000 0100";

Parameters:

number - The number to check.

Returns:

True if the number is a power of two, false otherwise.

log2

public static int log2(int bits)

A quick and simple way to calculate log2 of integers.

Parameters:

bits - the integer

Returns:

log2(bits)

pow2

public static int pow2(int power)

A quick way to calculate the power of two (2^power), by using bit shifts.

Parameters:

power - The power.

Returns:

2^power