/**
* Assigns the given L2-norm to the first leaf that does not have an L2-norm value yet (i.e.
* l2norm is negative). The search is done recursively and in the same order as that of the
* calcBasisWaveForms() method, so that this method is used to assigne the l2norm of the
* previously computed waveforms.
*
* <p>This method can not be called on an element that ahs a non-negative value in l2Norm, since
* that means that we are done.
*
* @param l2n The L2-norm to assign.
*/
private void assignL2Norm(float l2n) {
if (l2Norm < 0) {
// We are not finished with this element yet
if (isNode) {
// We are on a node => search on childs
if (subb_LL.l2Norm < 0f) {
subb_LL.assignL2Norm(l2n);
} else if (subb_HL.l2Norm < 0f) {
subb_HL.assignL2Norm(l2n);
} else if (subb_LH.l2Norm < 0f) {
subb_LH.assignL2Norm(l2n);
} else if (subb_HH.l2Norm < 0f) {
subb_HH.assignL2Norm(l2n);
// If child now is done, we are done
if (subb_HH.l2Norm >= 0f) {
l2Norm = 0f; // We are on a node, any non-neg value OK
}
} else {
// There is an error! If all childs have
// non-negative l2norm, then this node should have
// non-negative l2norm
throw new Error("You have found a bug in JJ2000!");
}
} else {
// This is a leaf, assign the L2-norm
l2Norm = l2n;
}
} else {
// This is an error! The assignL2Norm() method is
// never called on an element with non-negative l2norm
throw new Error("You have found a bug in JJ2000!");
}
}
/**
* 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.
*
* @param hfilter The horizontal wavelet filter used to decompose this subband. It has to be a
* AnWTFilter object.
* @param vfilter The vertical wavelet filter used to decompose this subband. It has to be a
* AnWTFilter object.
* @return A reference to the LL leaf (subb_LL).
* @see Subband#initChilds
*/
protected Subband split(WaveletFilter hfilter, WaveletFilter vfilter) {
// Test that this is a node
if (isNode) {
throw new IllegalArgumentException();
}
// Modify this element into a node and set the filters
isNode = true;
this.hFilter = (AnWTFilter) hfilter;
this.vFilter = (AnWTFilter) vfilter;
// Create childs
subb_LL = new SubbandAn();
subb_LH = new SubbandAn();
subb_HL = new SubbandAn();
subb_HH = new SubbandAn();
// Assign parent
subb_LL.parent = this;
subb_HL.parent = this;
subb_LH.parent = this;
subb_HH.parent = this;
// Initialize childs
initChilds();
// Return reference to LL subband
return subb_LL;
}
/**
* Calculates the parameters of the SubbandAn objects that depend on the Quantizer. The 'stepWMSE'
* field is calculated for each subband which is a leaf in the tree rooted at 'sb', for the
* specified component. The subband tree 'sb' must be the one for the component 'n'.
*
* @param sb The root of the subband tree.
* @param c The component index
* @see SubbandAn#stepWMSE
*/
protected void calcSbParams(SubbandAn sb, int c) {
float baseStep;
if (sb.stepWMSE > 0f) // parameters already calculated
return;
if (!sb.isNode) {
if (isReversible(tIdx, c)) {
sb.stepWMSE = (float) Math.pow(2, -(src.getNomRangeBits(c) << 1)) * sb.l2Norm * sb.l2Norm;
} else {
baseStep = ((Float) qsss.getTileCompVal(tIdx, c)).floatValue();
if (isDerived(tIdx, c)) {
sb.stepWMSE =
baseStep
* baseStep
* (float) Math.pow(2, (sb.anGainExp - sb.level) << 1)
* sb.l2Norm
* sb.l2Norm;
} else {
sb.stepWMSE = baseStep * baseStep;
}
}
} else {
calcSbParams((SubbandAn) sb.getLL(), c);
calcSbParams((SubbandAn) sb.getHL(), c);
calcSbParams((SubbandAn) sb.getLH(), c);
calcSbParams((SubbandAn) sb.getHH(), c);
sb.stepWMSE = 1f; // Signal that we already calculated this branch
}
}
/**
* Performs the forward wavelet transform on the whole band. It iteratively decomposes the
* subbands from the top node to the leaves.
*
* @param band The band containing the float data to decompose
* @param subband The structure containing the coordinates of the current subband in the whole
* band to decompose.
* @param c The index of the current component to decompose
*/
private void waveletTreeDecomposition(DataBlk band, SubbandAn subband, int c) {
// If the current subband is a leaf then nothing to be done (a leaf is
// not decomposed).
if (!subband.isNode) return;
else {
// Perform the 2D wavelet decomposition of the current subband
wavelet2DDecomposition(band, (SubbandAn) subband, c);
// Perform the decomposition of the four resulting subbands
waveletTreeDecomposition(band, (SubbandAn) subband.getHH(), c);
waveletTreeDecomposition(band, (SubbandAn) subband.getLH(), c);
waveletTreeDecomposition(band, (SubbandAn) subband.getHL(), c);
waveletTreeDecomposition(band, (SubbandAn) subband.getLL(), c);
}
}
/**
* Calculates the basis waveform of the first leaf for which the L2-norm has not been calculated
* yet. This method searches recursively for the first leaf for which the value has not been
* calculated yet, and then calculates the L2-norm on the return path.
*
* <p>The wfs argument should be a size 2 array of float arrays (i.e. 2D array) and it must be of
* length 2 (or more). When returning, wfs[0] will contain the line waveform, and wfs[1] will
* contain the column waveform.
*
* <p>This method can not be called on an element that ahs a non-negative value in l2Norm, since
* that means that we are done.
*
* @param wfs An size 2 array where the line and column waveforms will be returned.
*/
private void calcBasisWaveForms(float wfs[][]) {
if (l2Norm < 0) {
// We are not finished with this element yet
if (isNode) {
// We are on a node => search on childs
if (subb_LL.l2Norm < 0f) {
subb_LL.calcBasisWaveForms(wfs);
wfs[0] = hFilter.getLPSynWaveForm(wfs[0], null);
wfs[1] = vFilter.getLPSynWaveForm(wfs[1], null);
} else if (subb_HL.l2Norm < 0f) {
subb_HL.calcBasisWaveForms(wfs);
wfs[0] = hFilter.getHPSynWaveForm(wfs[0], null);
wfs[1] = vFilter.getLPSynWaveForm(wfs[1], null);
} else if (subb_LH.l2Norm < 0f) {
subb_LH.calcBasisWaveForms(wfs);
wfs[0] = hFilter.getLPSynWaveForm(wfs[0], null);
wfs[1] = vFilter.getHPSynWaveForm(wfs[1], null);
} else if (subb_HH.l2Norm < 0f) {
subb_HH.calcBasisWaveForms(wfs);
wfs[0] = hFilter.getHPSynWaveForm(wfs[0], null);
wfs[1] = vFilter.getHPSynWaveForm(wfs[1], null);
} else {
// There is an error! If all childs have
// non-negative l2norm, then this node should have
// non-negative l2norm
throw new Error("You have found a bug in JJ2000!");
}
} else {
// This is a leaf, just use diracs (null is
// equivalent to dirac)
wfs[0] = new float[1];
wfs[0][0] = 1.0f;
wfs[1] = new float[1];
wfs[1][0] = 1.0f;
}
} else {
// This is an error! The calcBasisWaveForms() method is
// never called on an element with non-negative l2norm
throw new Error("You have found a bug in JJ2000!");
}
}
/**
* Returns the next subband that will be used to get the next code-block to return by the
* getNext[Intern]CodeBlock method.
*
* @param c The component
* @return Its returns the next subband that will be used to get the next code-block to return by
* the getNext[Intern]CodeBlock method.
*/
private SubbandAn getNextSubband(int c) {
int down = 1;
int up = 0;
int direction = down;
SubbandAn nextsb;
nextsb = currentSubband[c];
// If it is the first call to this method
if (nextsb == null) {
nextsb = this.getAnSubbandTree(tIdx, c);
// If there is no decomposition level then send the whole image
if (!nextsb.isNode) {
return nextsb;
}
}
// Find the next subband to send
do {
// If the current subband is null then break
if (nextsb == null) {
break;
}
// If the current subband is a leaf then select the next leaf to
// send or go up in the decomposition tree if the leaf was a LL
// one.
else if (!nextsb.isNode) {
switch (nextsb.orientation) {
case Subband.WT_ORIENT_HH:
nextsb = (SubbandAn) nextsb.getParent().getLH();
direction = down;
break;
case Subband.WT_ORIENT_LH:
nextsb = (SubbandAn) nextsb.getParent().getHL();
direction = down;
break;
case Subband.WT_ORIENT_HL:
nextsb = (SubbandAn) nextsb.getParent().getLL();
direction = down;
break;
case Subband.WT_ORIENT_LL:
nextsb = (SubbandAn) nextsb.getParent();
direction = up;
break;
}
}
// Else if the current subband is a node
else if (nextsb.isNode) {
// If the direction is down the select the HH subband of the
// current node.
if (direction == down) {
nextsb = (SubbandAn) nextsb.getHH();
}
// Else the direction is up the select the next node to cover
// or still go up in the decomposition tree if the node is a LL
// subband
else if (direction == up) {
switch (nextsb.orientation) {
case Subband.WT_ORIENT_HH:
nextsb = (SubbandAn) nextsb.getParent().getLH();
direction = down;
break;
case Subband.WT_ORIENT_LH:
nextsb = (SubbandAn) nextsb.getParent().getHL();
direction = down;
break;
case Subband.WT_ORIENT_HL:
nextsb = (SubbandAn) nextsb.getParent().getLL();
direction = down;
break;
case Subband.WT_ORIENT_LL:
nextsb = (SubbandAn) nextsb.getParent();
direction = up;
break;
}
}
}
if (nextsb == null) {
break;
}
} while (nextsb.isNode);
return nextsb;
}
