Subband (SCIFIO Javadocs 0-SNAPSHOT API)

java.lang.Object
- io.scif.jj2000.j2k.wavelet.Subband

Direct Known Subclasses:

SubbandAn, SubbandSyn
```
public abstract class Subband
extends Object
```
This abstract class represents a subband in a bidirectional tree structure that describes the subband decomposition for a wavelet transform. This class is implemented by the SubbandAn and SubbandSyn classes, which are for the analysis and synthesis sides, respectively.
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 ther are no descendants.
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.

See Also:

SubbandAn, SubbandSyn

Field Summary

Fields
Modifier and Type	Field and Description
`int`	`anGainExp` The base 2 exponent of the analysis gain of the subband.
`int`	`h` The height of the subband
`boolean`	`isNode` True if it is a node in the tree, false if it is a leaf.
`int`	`level` The level in the tree to which this subband belongs, which is the number of wavelet decompositions performed to produce this subband.
`int`	`nomCBlkH` The nominal code-block height
`int`	`nomCBlkW` The nominal code-block width
`Point`	`numCb` The number of code-blocks (in both directions) contained in this subband.
`int`	`orientation` The orientation of this subband (WT_ORIENT_LL, WT_ORIENT_HL, WT_ORIENT_LH, WT_ORIENT_HH).
`int`	`resLvl` The resolution level to which this subband contributes.
`int`	`sbandIdx` The subband index within its resolution level.
`int`	`ulcx` The horizontal coordinate of the upper-left corner of the subband, with respect to the canvas origin, in the component's grid and subband's decomposition level.
`int`	`ulcy` The vertical coordinate of the upper-left corner of the subband, with respect to the canvas origin, in the component's grid and subband's decomposition level.
`int`	`ulx` The horizontal coordinate of the upper-left corner of the subband
`int`	`uly` The vertical coordinate of the upper-left corner of the subband
`int`	`w` The width of the subband
`static int`	`WT_ORIENT_HH` The ID for the HH orientation
`static int`	`WT_ORIENT_HL` The ID for the HL (horizontal high-pass) orientation
`static int`	`WT_ORIENT_LH` The ID for the LH (vertical high-pass) orientation
`static int`	`WT_ORIENT_LL` The ID for the LL orientation

Constructor Summary

Constructors
Constructor and Description
`Subband()` Creates a Subband element with all the default values.
`Subband(int w, int h, int ulcx, int ulcy, int lvls, WaveletFilter[] hfilters, WaveletFilter[] vfilters)` 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.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract Subband`	`getHH()` Returns the HH child subband of this subband.
`abstract Subband`	`getHL()` Returns the HL (horizontal high-pass) child subband of this subband.
`abstract WaveletFilter`	`getHorWFilter()` This function returns the horizontal wavelet filter relevant to this subband
`abstract Subband`	`getLH()` Returns the LH (vertical high-pass) child subband of this subband.
`abstract Subband`	`getLL()` Returns the LL child subband of this subband.
`Subband`	`getNextResLevel()` Returns the first leaf subband element in the next higher resolution level.
`abstract Subband`	`getParent()` Returns the parent of this subband.
`Subband`	`getSubband(int x, int y)` Returns a reference to the Subband element to which the specified point belongs.
`Subband`	`getSubbandByIdx(int rl, int sbi)` Returns a subband element in the tree, given its resolution level and subband index.
`abstract WaveletFilter`	`getVerWFilter()` This function returns the vertical wavelet filter relevant to this subband
`protected void`	`initChilds()` Initializes the childs of this node with the correct values.
`Subband`	`nextSubband()` Returns the next subband in the same resolution level, following the subband index order.
`protected abstract Subband`	`split(WaveletFilter hfilter, WaveletFilter vfilter)` Splits the current subband in its four subbands.
`String`	`toString()` Returns subband informations in a string.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - WT_ORIENT_LL
```
public static final int WT_ORIENT_LL
```
    The ID for the LL orientation
    
    See Also:
    
    Constant Field Values
  - WT_ORIENT_HL
```
public static final int WT_ORIENT_HL
```
    The ID for the HL (horizontal high-pass) orientation
    
    See Also:
    
    Constant Field Values
  - WT_ORIENT_LH
```
public static final int WT_ORIENT_LH
```
    The ID for the LH (vertical high-pass) orientation
    
    See Also:
    
    Constant Field Values
  - WT_ORIENT_HH
```
public static final int WT_ORIENT_HH
```
    The ID for the HH orientation
    
    See Also:
    
    Constant Field Values
  - isNode
```
public boolean isNode
```
    True if it is a node in the tree, false if it is a leaf. False by default.
  - orientation
```
public int orientation
```
    The orientation of this subband (WT_ORIENT_LL, WT_ORIENT_HL, WT_ORIENT_LH, WT_ORIENT_HH). It is WT_ORIENT_LL by default. The orientation of the top-level node (i.e. the full image before any decomposition) is WT_ORIENT_LL.
  - level
```
public int level
```
    The level in the tree to which this subband belongs, which is the number of wavelet decompositions performed to produce this subband. It is 0 for the top-level (i.e. root) node. It is 0 by default.
  - resLvl
```
public int resLvl
```
    The resolution level to which this subband contributes. Level 0 is the smallest resolution level (the one with the lowest frequency LL subband). It is 0 by default.
  - numCb
```
public Point numCb
```
    The number of code-blocks (in both directions) contained in this subband.
  - anGainExp
```
public int anGainExp
```
    The base 2 exponent of the analysis gain of the subband. The analysis gain of a subband is defined as the gain of the previous subband (i.e. the one from which this one was obtained) multiplied by the line gain and by the column gain. The line (column) gain is the gain of the line (column) filter that was used to obtain it, which is the DC gain for a low-pass filter and the Nyquist gain for a high-pass filter. It is 0 by default.
    Using the base 2 exponent of the value contrains the possible gains to powers of 2. However this is perfectly compatible to the filter normalization policy assumed here. See the split() method for more details.
    
    See Also:
    
    split(io.scif.jj2000.j2k.wavelet.WaveletFilter, io.scif.jj2000.j2k.wavelet.WaveletFilter)
  - sbandIdx
```
public int sbandIdx
```
    The subband index within its resolution level. This value uniquely identifies a subband within a resolution level and a decomposition level within it. Note that only leaf elements represent "real" subbands, while node elements represent only intermediate stages.
    It is defined recursively. The root node gets a value of 0. For a given node, with a subband index 'b', its LL descendant gets 4*b, its HL descendant 4*b+1, its LH descendant 4*b+2, and its HH descendant 4*b+3, for their subband indexes.
  - ulcx
```
public int ulcx
```
    The horizontal coordinate of the upper-left corner of the subband, with respect to the canvas origin, in the component's grid and subband's decomposition level. This is the real horizontal index of the first column of this subband. If even the horizontal decomposition of this subband should be done with the low-pass-first convention. If odd it should be done with the high-pass-first convention.
  - ulcy
```
public int ulcy
```
    The vertical coordinate of the upper-left corner of the subband, with respect to the canvas origin, in the component's grid and subband's decomposition level. This is the real vertical index of the first column of this subband. If even the vertical decomposition of this subband should be done with the low-pass-first convention. If odd it should be done with the high-pass-first convention.
  - ulx
```
public int ulx
```
    The horizontal coordinate of the upper-left corner of the subband
  - uly
```
public int uly
```
    The vertical coordinate of the upper-left corner of the subband
  - w
```
public int w
```
    The width of the subband
  - h
```
public int h
```
    The height of the subband
  - nomCBlkW
```
public int nomCBlkW
```
    The nominal code-block width
  - nomCBlkH
```
public int nomCBlkH
```
    The nominal code-block height
- Constructor Detail
  - Subband
```
public Subband()
```
    Creates a Subband element with all the default values. The dimensions are (0,0), the upper left corner is (0,0) and the upper-left corner with respect to the canvas is (0,0) too.
  - Subband
```
public Subband(int w,
               int h,
               int ulcx,
               int ulcy,
               int lvls,
               WaveletFilter[] hfilters,
               WaveletFilter[] vfilters)
```
    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.
    For the analysis subband gain calculation it is assumed that analysis filters are normalized with a DC gain of 1 and a Nyquist gain of 2.
    This constructor does not initialize the value of the magBits member variable. This variable is normally initialized by the quantizer, on the encoder side, or the bit stream reader, on the decoder side.
    
    Parameters:
    
    w - The top-level width
    
    h - The top-level height
    
    ulcx - The horizontal coordinate of the upper-left corner with respect to the canvas origin, in the component grid.
    
    ulcy - The vertical coordinate of the upper-left corner with respect to the canvas origin, in the component grid.
    
    lvls - The number of levels (or LL decompositions) in the tree.
    
    hfilters - The horizontal wavelet filters (analysis or synthesis) for each resolution level, starting at resolution level 0. If there are less elements in the array than there are resolution levels, the last element is used for the remaining resolution levels.
    
    vfilters - The vertical wavelet filters (analysis or synthesis) for each resolution level, starting at resolution level 0. If there are less elements in the array than there are resolution levels, the last element is used for the remaining resolution levels.
    
    See Also:
    
    WaveletTransform
- Method Detail
  - getParent
```
public abstract Subband getParent()
```
    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).
    
    Returns:
    
    The parent subband, or null for the root one.
  - getLL
```
public abstract Subband getLL()
```
    Returns the LL child subband of this subband.
    
    Returns:
    
    The LL child subband, or null if there are no childs.
  - getHL
```
public abstract Subband getHL()
```
    Returns the HL (horizontal high-pass) child subband of this subband.
    
    Returns:
    
    The HL child subband, or null if there are no childs.
  - getLH
```
public abstract Subband getLH()
```
    Returns the LH (vertical high-pass) child subband of this subband.
    
    Returns:
    
    The LH child subband, or null if there are no childs.
  - getHH
```
public abstract Subband getHH()
```
    Returns the HH child subband of this subband.
    
    Returns:
    
    The HH child subband, or null if there are no childs.
  - split
```
protected abstract Subband split(WaveletFilter hfilter,
                                 WaveletFilter vfilter)
```
    Splits the current subband in its four subbands. This creates the four childs (LL, HL, LH and HH) and converts the leaf in a node.
    
    Parameters:
    
    hfilter - The horizontal wavelet filter used to decompose this subband.
    
    vfilter - The vertical wavelet filter used to decompose this subband.
    
    Returns:
    
    A reference to the LL leaf (getLL()).
  - initChilds
```
protected void initChilds()
```
    Initializes the childs of this node with the correct values. The sizes of the child subbands are calculated by taking into account the position of the subband in the canvas.
    For the analysis subband gain calculation it is assumed that analysis filters are normalized with a DC gain of 1 and a Nyquist gain of 2.
  - nextSubband
```
public Subband nextSubband()
```
    Returns the next subband in the same resolution level, following the subband index order. If already at the last subband then null is returned. If this subband is not a leaf an IllegalArgumentException is thrown.
    
    Returns:
    
    The next subband in the same resolution level, following the subband index order, or null if already at last subband.
  - getNextResLevel
```
public Subband getNextResLevel()
```
    Returns the first leaf subband element in the next higher resolution level.
    
    Returns:
    
    The first leaf element in the next higher resolution level, or null if there is no higher resolution level.
  - getSubbandByIdx
```
public Subband getSubbandByIdx(int rl,
                               int sbi)
```
    Returns a subband element in the tree, given its resolution level and subband index. This method searches through the tree.
    
    Parameters:
    
    rl - The resolution level.
    
    sbi - The subband index, within the resolution level.
  - getSubband
```
public Subband getSubband(int x,
                          int y)
```
    Returns a reference to the Subband element to which the specified point belongs. The specified point must be inside this (i.e. the one defined by this object) subband. This method searches through the tree.
    
    Parameters:
    
    x - horizontal coordinate of the specified point.
    
    y - horizontal coordinate of the specified point.
  - toString
```
public String toString()
```
    Returns subband informations in a string.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    Subband informations
  - getHorWFilter
```
public abstract WaveletFilter getHorWFilter()
```
    This function returns the horizontal wavelet filter relevant to this subband
    
    Returns:
    
    The horizontal wavelet filter
  - getVerWFilter
```
public abstract WaveletFilter getVerWFilter()
```
    This function returns the vertical wavelet filter relevant to this subband
    
    Returns:
    
    The vertical wavelet filter

Class Subband

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

WT_ORIENT_LL

WT_ORIENT_HL

WT_ORIENT_LH

WT_ORIENT_HH

isNode

orientation

level

resLvl

numCb

anGainExp

sbandIdx

ulcx

ulcy

ulx

uly

w

h

nomCBlkW

nomCBlkH

Constructor Detail

Subband

Subband

Method Detail

getParent

getLL

getHL

getLH

getHH

split

initChilds

nextSubband

getNextResLevel

getSubbandByIdx

getSubband

toString

getHorWFilter

getVerWFilter