public FFT(COMPLEX[,] Input)
{
nx = Width = Input.GetLength(0);
ny = Height = Input.GetLength(1);
Fourier = Input;
}
public void FFTPlot(COMPLEX[,] Output)
{
int i, j;
float max;
FFTLog = new float[nx, ny];
FFTPhaseLog = new float[nx, ny];
FourierMagnitude = new float[nx, ny];
FourierPhase = new float[nx, ny];
FFTNormalized = new int[nx, ny];
FFTPhaseNormalized = new int[nx, ny];
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
FourierMagnitude[i, j] = Output[i, j].Magnitude();
FourierPhase[i, j] = Output[i, j].Phase();
FFTLog[i, j] = (float)Math.Log(1 + FourierMagnitude[i, j]);
FFTPhaseLog[i, j] = (float)Math.Log(1 + Math.Abs(FourierPhase[i, j]));
}
max = FFTLog[0, 0];
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
if (FFTLog[i, j] > max)
max = FFTLog[i, j];
}
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
FFTLog[i, j] = FFTLog[i, j] / max;
}
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
FFTNormalized[i, j] = (int)(2000 * FFTLog[i, j]);
}
FourierPlot = Displayimage(FFTNormalized);
FFTPhaseLog[0, 0] = 0;
max = FFTPhaseLog[1, 1];
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
if (FFTPhaseLog[i, j] > max)
max = FFTPhaseLog[i, j];
}
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
FFTPhaseLog[i, j] = FFTPhaseLog[i, j] / max;
}
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
FFTPhaseNormalized[i, j] = (int)(255 * FFTPhaseLog[i, j]);
}
PhasePlot = Displayimage(FFTPhaseNormalized);
}
public void InverseFFT(COMPLEX[,] Fourier)
{
int i, j;
Output = new COMPLEX[nx, ny];
Output = FFT2D(Fourier, nx, ny, -1);
for (i = 0; i <= Width - 1; i++)
for (j = 0; j <= Height - 1; j++)
{
GreyImage[i, j] = (int)Output[i, j].Magnitude();
}
Obj = Displayimage(GreyImage);
return;
}
public COMPLEX[,] FFT2D(COMPLEX[,] c, int nx, int ny, int dir)
{
int i, j;
int m;
double[] real;
double[] imag;
COMPLEX[,] output;
output = c;
real = new double[nx];
imag = new double[nx];
for (j = 0; j < ny; j++)
{
for (i = 0; i < nx; i++)
{
real[i] = c[i, j].real;
imag[i] = c[i, j].imag;
}
m = (int)Math.Log((double)nx, 2);
FFT1D(dir, m, ref real, ref imag);
for (i = 0; i < nx; i++)
{
// c[i,j].real = real[i];
// c[i,j].imag = imag[i];
output[i, j].real = real[i];
output[i, j].imag = imag[i];
}
}
real = new double[ny];
imag = new double[ny];
for (i = 0; i < nx; i++)
{
for (j = 0; j < ny; j++)
{
//real[j] = c[i,j].real;
//imag[j] = c[i,j].imag;
real[j] = output[i, j].real;
imag[j] = output[i, j].imag;
}
m = (int)Math.Log((double)ny, 2);
FFT1D(dir, m, ref real, ref imag);
for (j = 0; j < ny; j++)
{
//c[i,j].real = real[j];
//c[i,j].imag = imag[j];
output[i, j].real = real[j];
output[i, j].imag = imag[j];
}
}
// return(true);
return (output);
}
