/// <summary>
/// 一次元FFT
/// </summary>
/// <param name="src"></param>
/// <param name="direction"></param>
/// <returns></returns>
public static Complex[] FFT(Complex[] src, FourierDirectionEnum direction)
{
p.MaxDegreeOfParallelism = System.Environment.ProcessorCount;
Complex[] dest = fft(src, direction);
//ComplexArray.Scale(dest, 1 / Math.Sqrt(src.Length));
for (int i = 0; i < dest.Length; i++)
{
dest[i] *= 1 / Math.Sqrt(src.Length);
}
return(dest);
}
private static Complex[] fft(Complex[] src, FourierDirectionEnum direction)
{
sign = direction == FourierDirectionEnum.Forward ? -1 : 1;
return(fft(src));
}
/// <summary>
/// 2次元FFT
/// </summary>
/// <param name="src"></param>
/// <param name="direction"></param>
/// <returns></returns>
public static Complex[][] FFT(Complex[][] src, double[][] filter, FourierDirectionEnum direction)
{
if (src == null || src.Length == 0 || src[0] == null || src[0].Length == 0)
{
return(null);
}
int centerX = src[0].Length / 2, centerY = src.Length / 2;
//まずFilterを作用させる && ４分割して組みなおす
Complex[][] src2 = new Complex[src.Length][];
for (int i = 0; i < src.Length; i++)
{
src2[i] = new Complex[src[i].Length];
}
for (int i = 0; i < src.Length; i++)
{
for (int j = 0; j < src[i].Length; j++)
{
if (direction == FourierDirectionEnum.Inverse)
{
src2[i < centerY ? i + centerY : i - centerY][j < centerX ? j + centerX : j - centerX] = filter == null ? src[i][j] : (1 - filter[i][j]) * src[i][j];
}
else
{
src2[i][j] = filter == null ? src[i][j] : (1 - filter[i][j]) * src[i][j];
}
}
}
src = null;
sign = direction == FourierDirectionEnum.Forward ? -1 : 1;
FFTdelegate[] d = new FFTdelegate[ThreadTotal];
IAsyncResult[] ar = new IAsyncResult[ThreadTotal];
for (int i = 0; i < ThreadTotal; i++)
{
d[i] = new FFTdelegate(FFT);
}
//まず各行ごとにFFT
Complex[][] dest1 = new Complex[src2.Length][];
for (int i = 0; i < dest1.Length; i++)
{
for (int j = 0; j < ThreadTotal && i + j < dest1.Length; j++)
{
ar[j] = d[j].BeginInvoke(src2[i + j], direction, ref dest1[i + j], null, null);//スレッド起動
}
for (int j = 0; j < ThreadTotal && i + j < dest1.Length; j++)
{
d[j].EndInvoke(ref dest1[i + j], ar[j]);//スレッド終了待ち
if (ProgressEvent != null)
{
ProgressEvent();
}
}
i += ThreadTotal - 1;
}
//次に各列ごとにFFT
Complex[][] dest2 = new Complex[src2[0].Length][];
for (int i = 0; i < dest2.Length; i++)
{
dest2[i] = new Complex[src2.Length];
for (int j = 0; j < src2.Length; j++)
{
dest2[i][j] = dest1[j][i];
}
}
for (int i = 0; i < dest2.Length; i++)
{
for (int j = 0; j < ThreadTotal && i + j < dest2.Length; j++)
{
ar[j] = d[j].BeginInvoke(dest2[i + j], direction, ref dest2[i + j], null, null);//スレッド起動
}
for (int j = 0; j < ThreadTotal && i + j < dest2.Length; j++)
{
d[j].EndInvoke(ref dest2[i + j], ar[j]);//スレッド終了待ち
if (ProgressEvent != null)
{
ProgressEvent();
}
}
i += ThreadTotal - 1;
}
//dest2の行と列を入れ替えてdest1に格納し返す
for (int i = 0; i < src2.Length; i++)
{
for (int j = 0; j < src2[0].Length; j++)
{
dest1[i][j] = dest2[j][i];
}
}
dest2 = null;
if (direction == FourierDirectionEnum.Inverse)
{
return(dest1);
}
else //最後に入れ替える必要がある時は
{
Complex[][] dest3 = new Complex[src2.Length][];
for (int i = 0; i < dest3.Length; i++)
{
dest3[i] = new Complex[src2[i].Length];
}
for (int i = 0; i < src2.Length; i++)
{
for (int j = 0; j < src2[i].Length; j++)
{
dest3[i < centerY ? i + centerY : i - centerY][j < centerX ? j + centerX : j - centerX] = dest1[i][j];
}
}
dest1 = null;
return(dest3);
}
}
private static void FFT(Complex[] src, FourierDirectionEnum direction, ref Complex[] dest)
{
dest = FFT(src, direction);
}
public static Complex[][] FFT(Complex[][] src, FourierDirectionEnum direction)
{
return(FFT(src, null, direction));
}
