/**
* 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);
}
}
