jj2000.j2k.wavelet.synthesis
Class InvWTHelper

java.lang.Object
  |
  +--jj2000.j2k.wavelet.synthesis.InvWTHelper

public class InvWTHelper
extends java.lang.Object

This abstract class provides default implementations of some of methods that are useful for inverse wavelet transforms. The implementations are general and can suit most inverse DWT implementation.


Field Summary
(package private)  boolean[][] reversible
          The reversible flag for each component in each tile.
(package private)  InvWTData src
          The source of wavelet transform coefficients for the transform for which this object is intended to be the helper.
 
Constructor Summary
InvWTHelper(InvWTData src)
          Instantiates a new 'InvWTHelper' object to work with the specified source of wavelet coefficients.
 
Method Summary
 boolean isReversible(int t, int c)
          Returns the reversibility of the wavelet transform for the specified tile-component.
private  boolean isSubbandReversible(Subband subband)
          Returns the reversibility of the current subband.
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

src

InvWTData src
The source of wavelet transform coefficients for the transform for which this object is intended to be the helper.

reversible

boolean[][] reversible
The reversible flag for each component in each tile. The first index is the tile index, the second one is the component index. The reversibility of the components for each tile are calculated on a as needed basis.
Constructor Detail

InvWTHelper

public InvWTHelper(InvWTData src)
Instantiates a new 'InvWTHelper' object to work with the specified source of wavelet coefficients.
Parameters:
src - The source of wavelet coefficients for the wavelet transform to "help".
Method Detail

isSubbandReversible

private boolean isSubbandReversible(Subband subband)
Returns the reversibility of the current subband. It computes iteratively the reversibility of the child subbands. For each subband it tests the reversibility of the horizontal and vertical synthesis filters used to reconstruct this subband.
Parameters:
subband - The current subband.
Returns:
true if all the filters used to reconstruct the current subband are reversible

isReversible

public boolean isReversible(int t,
                            int c)
Returns the reversibility of the wavelet transform for the specified tile-component. A wavelet transform is reversible when it is suitable for lossless and lossy-to-lossless compression.
Parameters:
t - The index of the tile.
c - The index of the component.
Returns:
true is the wavelet transform is reversible, false if not.