# CSJ2K.j2k.wavelet.analysis.SubbandAn ## Content

SubbandAn Class

This class represents a subband in a bidirectional tree structure that describes the subband decomposition for a wavelet transform, specifically for the analysis side.

       <p>The element can be either a node or a leaf of the tree. If it is a node
       then ther are 4 descendants (LL, HL, LH and HH). If it is a leaf there are
       no descendants.</p>

       <p>The tree is bidirectional. Each element in the tree structure has a
       "parent", which is the subband from which the element was obtained by
       decomposition. The only exception is the root element which has no parent
       (i.e.it's null), for obvious reasons.</p>
Inheritance
object
Subband
SubbandAn
Namespace: CSJ2K.j2k.wavelet.analysis
Assembly: C1.C1Pdf.4.8.dll
Syntax
public class SubbandAn : Subband
Public Class SubbandAn
    Inherits Subband

Constructors

Name Description
SubbandAn()

Creates a SubbandAn element with all the default values. The dimensions are (0,0) and the upper left corner is (0,0).
SubbandAn(int, int, int, int, int, WaveletFilter[], WaveletFilter[])

Creates the top-level node and the entire subband tree, with the top-level dimensions, the number of decompositions, and the decomposition tree as specified.

       <p>This constructor just calls the same constructor of the super class,
       and then calculates the L2-norm (or energy weight) of each leaf.</p>

       <p>This constructor does not initialize the value of the magBits or
       stepWMSE member variables. This variables are normally initialized by
       the quantizer (see Quantizer).</p>

Fields

Name Description
hFilter

The horizontal analysis filter used to decompose this subband. This is applicable to "node" elements only. The default value is null.
l2Norm

The L2-norm of the synthesis basis waveform of this subband, applicable to "leafs" only. By default it is -1 (i.e. not calculated yet).
parentband

The reference to the parent of this subband. It is null for the root element. It is null by default.
stepWMSE

The contribution to the MSE or WMSE error that would result in the image if there was an error of exactly one quantization step size in the sample of the subband. This value is expressed relative to a nominal dynamic range in the image domain of exactly 1.0. This field contains valid data only after quantization 9See Quantizer).
subb_HH

The reference to the HH subband resulting from the decomposition of this subband. It is null by default.
subb_HL

The reference to the HL subband (horizontal high-pass) resulting from the decomposition of this subband. It is null by default.
subb_LH

The reference to the LH subband (vertical high-pass) resulting from the decomposition of this subband. It is null by default.
subb_LL

The reference to the LL subband resulting from the decomposition of this subband. It is null by default.
vFilter

The vertical analysis filter used to decompose this subband. This is applicable to "node" elements only. The default value is null.

Properties

Name Description
HH

Returns the HH child subband of this subband.
HL

Returns the HL (horizontal high-pass) child subband of this subband.
HorWFilter

This function returns the horizontal wavelet filter relevant to this subband
LH

Returns the LH (vertical high-pass) child subband of this subband.
LL

Returns the LL child subband of this subband.
Parent

Returns the parent of this subband. The parent of a subband is the subband from which this one was obtained by decomposition. The root element has no parent subband (null).
VerWFilter

This function returns the vertical wavelet filter relevant to this subband

Methods

Name Description
split(WaveletFilter, WaveletFilter)

Splits the current subband in its four subbands. It changes the status of this element (from a leaf to a node, and sets the filters), creates the childs and initializes them. An IllegalArgumentException is thrown if this subband is not a leaf.

       <p>It uses the initChilds() method to initialize the childs.</p>