private static double ManyLowQualityBlocksFunction(double x)
{
if (x < 22)
{
return(0);
}
if (x >= 22 && x < 25)
{
return(3 * Math.Sqrt(Math.PI * 2) * Gaussian.Gaussian1D(-x + 25, 3));
}
return(1);
}
private static double LittleLowQualityBlocksFunction(double x)
{
if (x < 22)
{
return(1);
}
if (x >= 22 && x < 26)
{
return(3 * Math.Sqrt(Math.PI * 2) * Gaussian.Gaussian1D((x - 22), 3));
}
return(0);
}
private static double GetSpatialContribution(Minutia m, Tuple <int, int> currentCell)
{
double distance = GetDistance(m.X, m.Y, currentCell.Item1, currentCell.Item2);
return(Gaussian.Gaussian1D(distance, Constants.SigmaS));
}
private double GaussianLocation(Minutia minutia, PointF point)
{
return(Gaussian.Gaussian1D(VectorHelper.PointDistance(new PointF(minutia.X, minutia.Y), point),
SigmaLocation));
}
private static void DirectionFiltering(double[,] l1, Complex[,] ls, double tau1, double tau2)
{
var l1Copy = new double[l1.GetLength(0), l1.GetLength(1)];
for (int x = 0; x < l1.GetLength(0); x++)
{
for (int y = 0; y < l1.GetLength(1); y++)
{
l1Copy[x, y] = l1[x, y];
}
}
var kernel = new double[directionSize];
var ksum = 0d;
for (int i = 0; i < directionSize; i++)
{
ksum += kernel[i] = Gaussian.Gaussian1D(i - directionSize / 2, sigmaDirection);
}
for (int i = 0; i < directionSize; i++)
{
kernel[i] /= ksum;
}
for (int x = 0; x < l1.GetLength(0); x++)
{
for (int y = 0; y < l1.GetLength(1); y++)
{
if (ls[x, y].Magnitude < tau1)
{
l1[x, y] = 0;
}
else
{
double sum = 0;
int area = 0;
for (int dx = -ringOuterRadius; dx <= ringOuterRadius; dx++)
{
for (int dy = -ringOuterRadius; dy <= ringOuterRadius; dy++)
{
if (Math.Abs(dy) < ringInnerRadius || Math.Abs(dx) < ringInnerRadius)
{
continue;
}
int xx = x + dx;
if (xx < 0)
{
xx = 0;
}
if (xx >= l1.GetLength(0))
{
xx = l1.GetLength(0) - 1;
}
int yy = y + dy;
if (yy < 0)
{
yy = 0;
}
if (yy >= l1.GetLength(1))
{
yy = l1.GetLength(1) - 1;
}
sum += ls[xx, yy].Magnitude;
area++;
}
}
if (sum / area < tau2)
{
l1[x, y] = 0;
}
else
{
var phase = ls[x, y].Phase / 2 - Math.PI / 2;
if (phase > Math.PI * 39 / 40)
{
phase -= Math.PI;
}
if (phase < -Math.PI / 40)
{
phase += Math.PI;
}
var direction = (int)Math.Round(phase / (Math.PI / 20));
var avg = 0.0d;
for (int i = 0; i < directionSize; i++)
{
var p = directions[i, direction];
int xx = x + p.X;
if (xx < 0)
{
xx = 0;
}
if (xx >= l1.GetLength(0))
{
xx = l1.GetLength(0) - 1;
}
int yy = y - p.Y;
if (yy < 0)
{
yy = 0;
}
if (yy >= l1.GetLength(1))
{
yy = l1.GetLength(1) - 1;
}
avg += kernel[i] * l1Copy[xx, yy];
}
l1[x, y] = avg;
}
}
}
}
}
