public KeypointN(Keypoint kp)
{
if (kp.HasFV != true)
{
throw (new ArgumentException("While trying to generate integer " +
"vector: source keypoint has no feature vector yet"));
}
x = kp.X;
y = kp.Y;
scale = kp.Scale;
orientation = kp.Orientation;
dim = kp.FVLinearDim;
descriptor = new int[kp.FVLinearDim];
for (int d = 0; d < kp.FVLinearDim; ++d)
{
descriptor[d] = (int)(255.0 * kp.FVLinearGet(d));
if (descriptor[d] < 0 || descriptor[d] > 255)
{
throw (new ArgumentOutOfRangeException
("Resulting integer descriptor k is not 0 <= k <= 255"));
}
}
}
private void CapAndNormalizeFV(Keypoint kp, double fvGradHicap)
{
double norm = 0.0;
for (int n = 0; n < kp.FVLinearDim; ++n)
{
norm += Math.Pow(kp.FVLinearGet(n), 2.0);
}
norm = Math.Sqrt(norm);
if (norm == 0.0)
{
throw (new InvalidOperationException
("CapAndNormalizeFV cannot normalize with norm = 0.0"));
}
for (int n = 0; n < kp.FVLinearDim; ++n)
{
kp.FVLinearSet(n, kp.FVLinearGet(n) / norm);
}
for (int n = 0; n < kp.FVLinearDim; ++n)
{
if (kp.FVLinearGet(n) > fvGradHicap)
{
kp.FVLinearSet(n, fvGradHicap);
}
}
norm = 0.0;
for (int n = 0; n < kp.FVLinearDim; ++n)
{
norm += Math.Pow(kp.FVLinearGet(n), 2.0);
}
norm = Math.Sqrt(norm);
for (int n = 0; n < kp.FVLinearDim; ++n)
{
kp.FVLinearSet(n, kp.FVLinearGet(n) / norm);
}
}