public double[] synt_noise(Bitmap image, int samplerate)
{
int samples = (int)image.Width * samplerate / pixpersec;
Complex[] noise = GlobalMembersSpectrogram.get_pink_noise(samplerate * 10); // 10 sec loop
double filterscale = ((double)noise.Length * 2) / samplerate;
Filterbank filterbank = Filterbank.get_filterbank(frequency_axis, filterscale, basefreq, bandwidth, overlap);
int top_index = (int)(maxfreq * filterscale);
double[] @out = new double[samples];
for (int bandidx = 0; bandidx < image.Height; ++bandidx)
{
//if (cancelled())
// return List<int>();
band_progress(bandidx, image.Height - 1);
// filter noise
Pair <int, int> range = filterbank.get_band(bandidx);
//std::cout << bandidx << "/"<<image.height()<<"\n";
Console.Out.WriteLine("(noise) sample: {0}", range.Second - range.First);
double[] filtered_noise = new double[noise.Length];
//std.copy(noise.begin()+range.first, noise.begin()+Math.Min(range.second, top_index), filtered_noise.begin()+range.first);
// ifft noise
double[] noise_mod = GlobalMembersSpectrogram.padded_IFFT(filtered_noise);
// resample spectrogram band
double[] envelope = GlobalMembersSpectrogram.resample(envelope_from_spectrogram(image, bandidx), samples);
// modulate with looped noise
for (uint i = 0; i < samples; ++i)
{
@out[i] += envelope[i] * noise_mod[i % noise_mod.Length];
}
}
GlobalMembersSpectrogram.normalize_signal(ref @out);
return(@out);
}
public double[] synt_sine(Bitmap image, int samplerate)
{
int samples = image.Width * samplerate / pixpersec;
Complex[] spectrum = new Complex[samples / 2 + 1];
double filterscale = ((double)spectrum.Length * 2) / samplerate;
Filterbank filterbank = Filterbank.get_filterbank(frequency_axis, filterscale, basefreq, bandwidth, overlap);
for (int bandidx = 0; bandidx < image.Height; ++bandidx)
{
//if (cancelled())
// return List<int>();
band_progress(bandidx, image.Height - 1);
double[] envelope = envelope_from_spectrogram(image, bandidx);
// random phase between +-pi
double phase = (2 * GlobalMembersSpectrogram.random_double() - 1) * Math.PI;
double[] bandsignal = new double[envelope.Length * 2];
for (int j = 0; j < 4; ++j)
{
double sine = Math.Cos(j * Math.PI / 2 + phase);
for (int i = j; i < bandsignal.Length; i += 4)
{
bandsignal[i] = envelope[i / 2] * sine;
}
}
Complex[] filterband = GlobalMembersSpectrogram.padded_FFT(bandsignal);
for (int i = 0; i < filterband.Length; ++i)
{
double x = (double)i / filterband.Length;
// normalized blackman window antiderivative
filterband[i] *= x - ((0.5 / (2.0 * Math.PI)) * Math.Sin(2.0 * Math.PI * x) + (0.08 / (4.0 * Math.PI)) * Math.Sin(4.0 * Math.PI * x) / 0.42);
}
Console.Out.WriteLine("spectrum size: {0}", spectrum.Length);
//std::cout << bandidx << ". filterband size: " << filterband.Length << "; start: " << filterbank->get_band(bandidx).first <<"; end: " << filterbank->get_band(bandidx).second << "\n";
double center = filterbank.get_center(bandidx);
double offset = Math.Max((uint)0, center - filterband.Length / 2);
Console.Out.WriteLine("offset: {0} = {1} hz", offset, offset / filterscale);
for (uint i = 0; i < filterband.Length; ++i)
{
if (offset + i > 0 && offset + i < spectrum.Length)
{
spectrum[(int)(offset + i)] += filterband[i];
}
}
}
double[] @out = GlobalMembersSpectrogram.padded_IFFT(spectrum);
Console.Out.WriteLine("samples: {0} -> {1}", @out.Length, samples);
GlobalMembersSpectrogram.normalize_signal(ref @out);
return(@out);
}
public Bitmap to_image(ref double[] signal, int samplerate)
{
Console.Out.WriteLine("Transforming input");
Complex[] spectrum = GlobalMembersSpectrogram.padded_FFT(signal);
//const size_t width = (spectrum.size()-1)*2*pixpersec/samplerate;
double w1 = spectrum.Length - 1;
double w2 = (double)pixpersec / (double)samplerate;
double w3 = w1 * 2 * w2;
int width = (int)w3;
// transformation of frequency in hz to index in spectrum
//const double filterscale = ((double)spectrum.size()*2)/samplerate;
double filterscale = ((double)spectrum.Length * 2) / samplerate;
Console.Out.WriteLine("filterscale: {0}", filterscale);
Filterbank filterbank = Filterbank.get_filterbank(frequency_axis, filterscale, basefreq, bandwidth, overlap);
int bands = (int)filterbank.num_bands_est(maxfreq);
int top_index = (int)(maxfreq * filterscale);
// maxfreq has to be at most nyquist
Debug.Assert(top_index <= spectrum.Length);
//std::vector<real_vec> image_data;
List <double[]> image_data = new List <double[]>();
for (int bandidx = 0;; ++bandidx)
{
band_progress(bandidx, bands);
// filtering
Pair <int, int> range = filterbank.get_band(bandidx);
Console.Out.WriteLine("-----");
Console.Out.WriteLine("spectrum size: {0}", spectrum.Length);
Console.Out.WriteLine("lowidx: {0:0.00} highidx: {1:0.00}", range.First, range.Second);
Console.Out.WriteLine("(real)lowfreq: {0:0.00} (real)highfreq: {1:0.00}", range.First / filterscale, range.Second / filterscale);
Console.Out.WriteLine("actual width: {0:0.00} hz", (range.Second - range.First) / filterscale);
Console.Out.WriteLine("vertical values: {0:0.00}", (range.Second - range.First));
Console.Out.WriteLine("crowd sample: {0:0.00}", (range.Second - range.First - 1) * 2);
Console.Out.WriteLine("theoretically staci: {0:0.00} hz samplerate", 2 * (range.Second - range.First) / filterscale);
Console.Out.WriteLine("width: {0}", width);
int filterbandLength = range.Second - range.First;
Complex[] filterband = new Complex[filterbandLength];
//std::copy(spectrum.begin()+range.first,
// spectrum.begin()+std::min(range.second, top_index),
// filterband.begin());
int sourceIndexStart = range.First;
int sourceIndexEnd = Math.Min(range.Second, top_index);
int length = sourceIndexEnd - sourceIndexStart;
Array.Copy(spectrum, sourceIndexStart, filterband, 0, length);
if (range.First > top_index)
{
break;
}
if (range.Second > top_index)
{
int start = top_index - range.First;
//std::fill(filterband.begin()+top_index-range.first,
// filterband.end(), Complex(0,0));
break; // TODO: fix above
}
// windowing
apply_window(ref filterband, range.First, filterscale);
// envelope detection + resampling
double[] envelope = GlobalMembersSpectrogram.resample(GlobalMembersSpectrogram.get_envelope(ref filterband), width);
image_data.Add(envelope);
}
GlobalMembersSpectrogram.normalize_image_cutoff_negative(ref image_data);
return(make_image(image_data));
}