public static unsafe DwtOutput Forward(double[] input, Wavelet wavelet, Int32 level)
{
Int32 Len = wavelet.DecompositionLow.Length;
Int32 CircleInd;
double[] output = new Double[input.Length];
Double[] Buff = new Double[input.Length];
Buffer.BlockCopy(input, 0, output, 0, input.Length * 8);
Double BufScal = 0;
Double BufDet = 0;
Double *DecLow = stackalloc Double[Len];
Double *DecHigh = stackalloc Double[Len];
for (int i = 0; i < Len; i++)
{
DecLow[i] = wavelet.DecompositionLow[i];
DecHigh[i] = wavelet.DecompositionHigh[i];
}
fixed(Double *pout = output, pbuf = Buff)
{
for (int lvl = 0; lvl < level; lvl++)
{
Int32 Bound = input.Length >> lvl;
Int32 StartIndex = -((Len >> 1) - 1);
Buffer.BlockCopy(output, 0, Buff, 0, Bound * 8);
for (int i = 0; i < Bound >> 1; i++)
{
for (int j = StartIndex, k = 0; k < Len; j++, k++)
{
if ((StartIndex < 0) || j >= Bound)
{
CircleInd = ((j % Bound) + Bound) % Bound;
}
else
{
CircleInd = j;
}
BufScal += DecLow[k] * pout[CircleInd];
BufDet += DecHigh[k] * pout[CircleInd];
}
StartIndex += 2;
pbuf[i] = BufScal;
pbuf[i + (Bound >> 1)] = BufDet;
BufScal = 0;
BufDet = 0;
}
Buffer.BlockCopy(Buff, 0, output, 0, Bound * 8);
}
}
DwtOutput res = new DwtOutput(output, level, wavelet);
return(res);
}
public static unsafe double[] Inverse(DwtOutput dwtInput)
{
var wavelet = dwtInput.Wavelet;
var input = dwtInput.FullVector;
var level = dwtInput.Level;
Int32 Len = wavelet.ReconstructionLow.Length;
Int32 CircleInd;
double[] output = new Double[input.Length];
Double[] Buff = new Double[input.Length];
Double[] BufferLow = new Double[input.Length];
Double[] BufferHigh = new Double[input.Length];
Buffer.BlockCopy(input, 0, output, 0, input.Length * 8);
Double Buf = 0;
Double *RecLow = stackalloc Double[Len];
Double *RecHigh = stackalloc Double[Len];
for (int i = 0; i < Len; i++)
{
RecLow[i] = wavelet.ReconstructionLow[i];
RecHigh[i] = wavelet.ReconstructionHigh[i];
}
fixed(Double *pbuf = Buff, pLow = BufferLow, pHigh = BufferHigh)
{
for (int lvl = level; lvl > 0; lvl--)
{
Int32 Bound = input.Length >> lvl;
Int32 StartIndex = -((Len >> 1) - 1);
for (int i = 0, j = 0; i < Bound << 1; i += 2, j++)
{
pLow[i] = 0;
pHigh[i] = 0;
pLow[i + 1] = output[j];
pHigh[i + 1] = output[Bound + j];
}
for (int i = 0; i < Bound << 1; i++)
{
for (int j = StartIndex, k = 0; k < Len; j++, k++)
{
if ((StartIndex < 0) || j >= (Bound << 1))
{
CircleInd = (j % (Bound << 1) + (Bound << 1)) % (Bound << 1);
}
else
{
CircleInd = j;
}
Buf += RecLow[k] * pLow[CircleInd] + RecHigh[k] * pHigh[CircleInd];
}
StartIndex += 1;
pbuf[i] = Buf;
Buf = 0;
}
Buffer.BlockCopy(Buff, 0, output, 0, Bound * 16);
}
}
return(output);
}
