jj2000.j2k.wavelet.Subband Maven / Gradle / Ivy
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/*
*
* $RCSfile: Subband.java,v $
* $Revision: 1.1 $
* $Date: 2005/02/11 05:02:27 $
* $State: Exp $
*
* Class: Subband
*
* Description: Asbtract element for a tree strcuture for
* a description of subbands.
*
*
*
* COPYRIGHT:
*
* This software module was originally developed by Raphaël Grosbois and
* Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
* Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
* Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
* Centre France S.A) in the course of development of the JPEG2000
* standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
* software module is an implementation of a part of the JPEG 2000
* Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
* Systems AB and Canon Research Centre France S.A (collectively JJ2000
* Partners) agree not to assert against ISO/IEC and users of the JPEG
* 2000 Standard (Users) any of their rights under the copyright, not
* including other intellectual property rights, for this software module
* with respect to the usage by ISO/IEC and Users of this software module
* or modifications thereof for use in hardware or software products
* claiming conformance to the JPEG 2000 Standard. Those intending to use
* this software module in hardware or software products are advised that
* their use may infringe existing patents. The original developers of
* this software module, JJ2000 Partners and ISO/IEC assume no liability
* for use of this software module or modifications thereof. No license
* or right to this software module is granted for non JPEG 2000 Standard
* conforming products. JJ2000 Partners have full right to use this
* software module for his/her own purpose, assign or donate this
* software module to any third party and to inhibit third parties from
* using this software module for non JPEG 2000 Standard conforming
* products. This copyright notice must be included in all copies or
* derivative works of this software module.
*
* Copyright (c) 1999/2000 JJ2000 Partners.
* */
package jj2000.j2k.wavelet;
import java.awt.Point;
/**
* 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 jj2000.j2k.wavelet.analysis.SubbandAn
* @see jj2000.j2k.wavelet.synthesis.SubbandSyn
* */
public abstract class Subband {
/** The ID for the LL orientation */
public final static int WT_ORIENT_LL = 0;
/** The ID for the HL (horizontal high-pass) orientation */
public final static int WT_ORIENT_HL = 1;
/** The ID for the LH (vertical high-pass) orientation */
public final static int WT_ORIENT_LH = 2;
/** The ID for the HH orientation */
public final static int WT_ORIENT_HH = 3;
/**
* True if it is a node in the tree, false if it is a leaf. False by
* default. */
public boolean isNode;
/**
* 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. */
// The default value is always 0, which is WT_ORIENT_LL.
public int orientation;
/**
* 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.
* */
public int level;
/**
* 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.
* */
public int resLvl;
/** The number of code-blocks (in both directions) contained in this
* subband. */
public Point numCb = null;
/**
* 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 #split
* */
public int anGainExp;
/**
* 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.
* */
public int sbandIdx = 0;
/**
* 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.
* */
public int ulcx;
/**
* 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.
* */
public int ulcy;
/** The horizontal coordinate of the upper-left corner of the subband */
public int ulx;
/** The vertical coordinate of the upper-left corner of the subband */
public int uly;
/** The width of the subband */
public int w;
/** The height of the subband */
public int h;
/** The nominal code-block width */
public int nomCBlkW;
/** The nominal code-block height */
public int nomCBlkH;
/**
* 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).
*
* @return The parent subband, or null for the root one.
* */
public abstract Subband getParent();
/**
* Returns the LL child subband of this subband.
*
* @return The LL child subband, or null if there are no childs.
* */
public abstract Subband getLL();
/**
* Returns the HL (horizontal high-pass) child subband of this subband.
*
* @return The HL child subband, or null if there are no childs.
* */
public abstract Subband getHL();
/**
* Returns the LH (vertical high-pass) child subband of this subband.
*
* @return The LH child subband, or null if there are no childs.
* */
public abstract Subband getLH();
/**
* Returns the HH child subband of this subband.
*
* @return The HH child subband, or null if there are no childs.
* */
public abstract Subband getHH();
/**
* 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.
*
* @param hfilter The horizontal wavelet filter used to decompose this
* subband.
*
* @param vfilter The vertical wavelet filter used to decompose this
* subband.
*
* @return A reference to the LL leaf (getLL()).
* */
protected abstract Subband split(WaveletFilter hfilter,
WaveletFilter vfilter);
/**
* 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.
* */
protected void initChilds() {
Subband subb_LL = getLL();
Subband subb_HL = getHL();
Subband subb_LH = getLH();
Subband subb_HH = getHH();
// LL subband
subb_LL.level = level+1;
subb_LL.ulcx = (ulcx+1)>>1;
subb_LL.ulcy = (ulcy+1)>>1;
subb_LL.ulx = ulx;
subb_LL.uly = uly;
subb_LL.w = ((ulcx+w+1)>>1)-subb_LL.ulcx;
subb_LL.h = ((ulcy+h+1)>>1)-subb_LL.ulcy;
// If this subband in in the all LL path (i.e. it's global orientation
// is LL) then child LL band contributes to a lower resolution level.
subb_LL.resLvl = (orientation == WT_ORIENT_LL) ? resLvl-1 : resLvl;
subb_LL.anGainExp = anGainExp;
subb_LL.sbandIdx = (sbandIdx<<2);
// HL subband
subb_HL.orientation = WT_ORIENT_HL;
subb_HL.level = subb_LL.level;
subb_HL.ulcx = ulcx>>1;
subb_HL.ulcy = subb_LL.ulcy;
subb_HL.ulx = ulx + subb_LL.w;
subb_HL.uly = uly;
subb_HL.w = ((ulcx+w)>>1)-subb_HL.ulcx;
subb_HL.h = subb_LL.h;
subb_HL.resLvl = resLvl;
subb_HL.anGainExp = anGainExp+1;
subb_HL.sbandIdx = (sbandIdx<<2)+1;
// LH subband
subb_LH.orientation = WT_ORIENT_LH;
subb_LH.level = subb_LL.level;
subb_LH.ulcx = subb_LL.ulcx;
subb_LH.ulcy = ulcy>>1;
subb_LH.ulx = ulx;
subb_LH.uly = uly + subb_LL.h;
subb_LH.w = subb_LL.w;
subb_LH.h = ((ulcy+h)>>1)-subb_LH.ulcy;
subb_LH.resLvl = resLvl;
subb_LH.anGainExp = anGainExp+1;
subb_LH.sbandIdx = (sbandIdx<<2)+2;
// HH subband
subb_HH.orientation = WT_ORIENT_HH;
subb_HH.level = subb_LL.level;
subb_HH.ulcx = subb_HL.ulcx;
subb_HH.ulcy = subb_LH.ulcy;
subb_HH.ulx = subb_HL.ulx;
subb_HH.uly = subb_LH.uly;
subb_HH.w = subb_HL.w;
subb_HH.h = subb_LH.h;
subb_HH.resLvl = resLvl;
subb_HH.anGainExp = anGainExp+2;
subb_HH.sbandIdx = (sbandIdx<<2)+3;
}
/**
* 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.
* */
public Subband() {
}
/**
* 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.
*
* @param w The top-level width
*
* @param h The top-level height
*
* @param ulcx The horizontal coordinate of the upper-left corner with
* respect to the canvas origin, in the component grid.
*
* @param ulcy The vertical coordinate of the upper-left corner with
* respect to the canvas origin, in the component grid.
*
* @param lvls The number of levels (or LL decompositions) in the tree.
*
* @param 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.
*
* @param 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 WaveletTransform
* */
public Subband(int w, int h, int ulcx, int ulcy, int lvls,
WaveletFilter hfilters[], WaveletFilter vfilters[]) {
int i,hi,vi;
Subband cur; // The current subband
// Initialize top-level node
this.w = w;
this.h = h;
this.ulcx = ulcx;
this.ulcy = ulcy;
this.resLvl = lvls;
// First create dyadic decomposition.
cur = this;
for (i=0; isb.resLvl || rl<0) {
throw new IllegalArgumentException("Resolution level index "+
"out of range");
}
// Returns directly if it is itself
if(rl==sb.resLvl && sbi==sb.sbandIdx) return sb;
if(sb.sbandIdx!=0) sb = sb.getParent();
while(sb.resLvl>rl) sb = sb.getLL();
while(sb.resLvl=ulx+w || y>=uly+h) {
throw new IllegalArgumentException();
}
cur = this;
while (cur.isNode) {
hhs = cur.getHH();
// While we are still at a node -> continue
if (x