public static Image getImage(int[] data, double begin = 0, double end = 1)
{
data = FToneAnalysis.getSoundPart(data);
int sampleLength = data.Length;
int begink = (int)(sampleLength * begin);
int endk = (int)(sampleLength * end);
int w = (endk - begink) * 2;
int h = 200;
Bitmap bitmap = new Bitmap(w, h);
Graphics g = Graphics.FromImage(bitmap);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
//draw x,y
g.DrawLine(new Pen(Color.Black, 5), new Point(0, 0), new Point(0, h));
g.DrawLine(new Pen(Color.Black, 5), new Point(0, h / 2), new Point(w, h / 2));
//draw wave
for (int i = begink; i < endk; i++)
{
Pen p = new Pen(Color.Green, 1);
g.DrawLine(p,
new Point((int)(((double)i - begink) * w / (endk - begink)), h / 2),
new Point((int)(((double)i - begink) * w / (endk - begink)), h / 2 + (int)((double)data[i] / 60 / 10)));
}
//draw cut
int[] res = FToneAnalysis.cutIt(data);
for (int i = 1; i < res.Length; i++)
{
if (res[i] > 0.5)
{
g.DrawLine(new Pen(Color.Red, 2),
new Point((int)(((double)res[i] - begink) * w / (endk - begink)), 0),
new Point((int)(((double)res[i] - begink) * w / (endk - begink)), h));
}
}
return(bitmap);
}
/// <summary>
/// 用倒谱获得频谱包络
/// </summary>
/// <param name="data"></param>
/// <returns></returns>
private static double[] GetEnvelopeFD(double[] data)
{
int n = data.Length;
double[] data1 = new double[n];
double[] data1i = new double[n];
for (int i = 0; i < n; i++)
{
data1[i] = Math.Log(data[i]);
}
for (int i = 0; i < n; i++)
{
data1i[i] = 0;
}
TWFFT.FFT(data1, data1i);
double therehold = 100;
double[] data2 = new double[n];
double[] data2i = new double[n];
// 低通滤波
for (int i = 0; i < n; i++)
{
if (i < therehold || i > n - therehold)
{
data2[i] = data1[i];
data2i[i] = data1i[i];
}
else
{
data2[i] = 0;
data2i[i] = 0;
}
}
//for (int i = 0; i < n; i++) data2i[i] = 0;
TWFFT.IFFT(data2, data2i);
var res = FToneAnalysis.MiddleFilter(data2, 3);
for (int i = 0; i < n; i++)
{
res[i] = Math.Pow(Math.E, res[i]);
}
return(res);
}
