Top Description Fields Constructors Methods
org.apache.commons.math3.transform

public final Enum DctNormalization

extends Enum<DctNormalization>
Class Inheritance

This enumeration defines the various types of normalizations that can be applied to discrete cosine transforms (DCT). The exact definition of these normalizations is detailed below.
Since
3.0
See Also
FastCosineTransformer

Field Summary

Modifier and TypeField and Description
public static final DctNormalization
ORTHOGONAL_DCT_I

Should be passed to the constructor of FastCosineTransformer to use the orthogonal normalization convention.

public static final DctNormalization
STANDARD_DCT_I

Should be passed to the constructor of FastCosineTransformer to use the standard normalization convention.

Constructor Summary

AccessConstructor and Description
private

Method Summary

Modifier and TypeMethod and Description
public static DctNormalization
public static DctNormalization[]
Inherited from java.lang.Enum:
clonecompareTodescribeConstableequalsfinalizegetDeclaringClasshashCodenameordinaltoStringvalueOf

Field Detail

ORTHOGONAL_DCT_Iback to summary
public static final DctNormalization ORTHOGONAL_DCT_I

Should be passed to the constructor of FastCosineTransformer to use the orthogonal normalization convention. The orthogonal DCT-I normalization convention is defined as follows

  • forward transform: yn = [2(N - 1)]-1/2 [x0 + (-1)nxN-1] + [2 / (N - 1)]1/2 ∑k=1N-2 xk cos[π nk / (N - 1)],
  • inverse transform: xk = [2(N - 1)]-1/2 [y0 + (-1)kyN-1] + [2 / (N - 1)]1/2 ∑n=1N-2 yn cos[π nk / (N - 1)],
which makes the transform orthogonal. N is the size of the data sample.
STANDARD_DCT_Iback to summary
public static final DctNormalization STANDARD_DCT_I

Should be passed to the constructor of FastCosineTransformer to use the standard normalization convention. The standard DCT-I normalization convention is defined as follows

  • forward transform: yn = (1/2) [x0 + (-1)nxN-1] + ∑k=1N-2 xk cos[π nk / (N - 1)],
  • inverse transform: xk = [1 / (N - 1)] [y0 + (-1)kyN-1] + [2 / (N - 1)] ∑n=1N-2 yn cos[π nk / (N - 1)],
where N is the size of the data sample.

Constructor Detail

DctNormalizationback to summary
private DctNormalization()

Method Detail

valueOfback to summary
public static DctNormalization valueOf(String name)
valuesback to summary
public static DctNormalization[] values()