public Wavelet(WaveletType name)
{
this.wavelet_type = name;
if (this.wavelet_type == WaveletType.Daubechie3) {
this.low_pass_filter_coef = daubechie3_low_pass_coefs;
this.high_pass_filter_coef = daubechie3_high_pass_coefs;
}
}
private static double[,] DecodeChannel(double[,] channel, WaveletType waveletType, int iterationsCount)
{
var lowerCoefs = GetCoefsByWaveletType(waveletType);
var higherCoefs = GetHighPassFilter(lowerCoefs);
double[] iLowerCoefs, iHigherCoefs;
GetInverseCoefs(lowerCoefs, higherCoefs, out iLowerCoefs, out iHigherCoefs);
var height = channel.GetLength(0);
var width = channel.GetLength(1);
var orderedChannel = new double[height, width];
height >>= iterationsCount - 1;
width >>= iterationsCount - 1;
for (var counter = 0; counter < iterationsCount; ++counter)
{
for (var i = 0; i < height; ++i)
{
for (var j = 0; j < width; ++j)
{
orderedChannel[i, j] = channel[i % 2 == 0 ? i / 2 : height / 2 + i / 2, j % 2 == 0 ? j / 2 : width / 2 + j / 2];
}
}
var line = new double[height];
for (var j = 0; j < width; ++j)
{
for (var i = 0; i < height; ++i)
{
line[i] = orderedChannel[i, j];
}
var resultLine = PairConvolution(line, iLowerCoefs, iHigherCoefs, iLowerCoefs.Length - 2);
for (var i = 0; i < height; ++i)
{
channel[i, j] = resultLine[i];
}
}
line = new double[width];
for (var i = 0; i < height; ++i)
{
for (var j = 0; j < width; ++j)
{
line[j] = channel[i, j];
}
var resultLine = PairConvolution(line, iLowerCoefs, iHigherCoefs, iLowerCoefs.Length - 2);
for (var j = 0; j < width; ++j)
{
channel[i, j] = resultLine[j];
}
}
height <<= 1;
width <<= 1;
}
return(channel);
}
static IntPtr GetNativeWaveletType(WaveletType waveletType)
{
switch (waveletType)
{
case WaveletType.Haar: return(Native.GetWaveletTypeHaar());
case WaveletType.Daubechies: return(Native.GetWaveletTypeDaubechies());
case WaveletType.BSpline: return(Native.GetWaveletTypeBSpline());
default: throw new ArgumentException("parameter 'waveletType' is not a valid wavelet type");
}
}
private static double[] GetCoefsByWaveletType(WaveletType waveletType)
{
switch (waveletType)
{
case WaveletType.Haar1:
return(new[]
{
1.0 / 2,
1.0 / 2,
});
case WaveletType.Haar2:
return(new[]
{
1.0 / Math.Sqrt(2.0),
1.0 / Math.Sqrt(2.0)
});
case WaveletType.D4:
return(new[]
{
(1 + Math.Sqrt(3)) / (4 * Math.Sqrt(2)),
(3 + Math.Sqrt(3)) / (4 * Math.Sqrt(2)),
(3 - Math.Sqrt(3)) / (4 * Math.Sqrt(2)),
(1 - Math.Sqrt(3)) / (4 * Math.Sqrt(2))
});
case WaveletType.D6:
return(new[]
{
0.47046721 / Math.Sqrt(2),
1.14111692 / Math.Sqrt(2),
0.650365 / Math.Sqrt(2),
-0.19093442 / Math.Sqrt(2),
-0.12083221 / Math.Sqrt(2),
0.0498175 / Math.Sqrt(2),
});
default:
throw new ArgumentOutOfRangeException("waveletType", waveletType, null);
}
}
public Wavelet(WaveletType waveletType, double[] decLowPass)
{
WaveletType = waveletType;
DecompositionLow = decLowPass;
DecompositionHigh = new double[decLowPass.Length];
ReconstructionLow = new double[decLowPass.Length];
ReconstructionHigh = new double[decLowPass.Length];
for (int i = 0; i < decLowPass.Length; i++)
{
DecompositionHigh[i] = decLowPass[decLowPass.Length - i - 1];
if (i % 2 != 0)
{
DecompositionHigh[i] *= -1;
}
ReconstructionLow[i] = decLowPass[decLowPass.Length - i - 1];
}
for (int i = 0; i < decLowPass.Length; i++)
{
ReconstructionHigh[i] = DecompositionHigh[decLowPass.Length - i - 1];
}
}
public WaveletTransformer(WaveletType waveletType, int waveletParameter)
{
this.wavelet = Native.CreateWavelet(GetNativeWaveletType(waveletType), (uint)waveletParameter);
}
