Module imagingbook.spectral

Package imagingbook.spectral.dct

Class Dct1dFast

java.lang.Object

imagingbook.spectral.dct.Dct1dFast

All Implemented Interfaces:

Dct1d

Direct Known Subclasses:

Dct1dFast.Double, Dct1dFast.Float

public abstract class Dct1dFast
extends Object

This is fast implementation of the DCT, based on the JTransforms package by Piotr Wendykier ( https://github.com/wendykierp/JTransforms). Note that this class has no public constructor - instantiate sub-class Dct1dFast.Float or Dct1dFast.Double instead, as shown below. See Sec. 20.1 of [1] for additional details.

Usage example (for float data):

 float[] data = {1, 2, 3, 4, 5, 3, 0};
 Dct1d.Float dct = new Dct1dFast.Float(data.length);
 dct.forward(data);
 dct.inverse(data);
 ...
 

[1] W. Burger, M.J. Burge, Digital Image Processing – An Algorithmic Introduction, 3rd ed, Springer (2022).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Dct1dFast.Double	One-dimensional DCT implementation using double data.
static class	Dct1dFast.Float	One-dimensional DCT implementation using float data.

Method Summary

Modifier and Type	Method	Description
int	getSize()	Returns the size of this DCT (length of data vectors).

Methods inherited from class java.lang.Object

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

Method Details

getSize

public int getSize()

Description copied from interface: Dct1d

Returns the size of this DCT (length of data vectors).

Specified by:

getSize in interface Dct1d

Returns:

the size of this DCT