/// <summary>
/// Extract features of type <see cref="MtripletsFeature"/> from the specified minutiae.
/// </summary>
/// <param name="minutiae">
/// The list of <see cref="Minutia"/> to extract the features from.
/// </param>
/// <returns>
/// Features of type <see cref="MtripletsFeature"/> extracted from the specified minutiae.
/// </returns>
public MtripletsFeature ExtractFeatures(List <Minutia> minutiae)
{
List <MTriplet> mtriplets = new List <MTriplet>();
Dictionary <int, int> triplets = new Dictionary <int, int>();
foreach (var triangle in Delaunay2D.Triangulate(minutiae))
{
var idxArr = new short[]
{
(short)triangle.A,
(short)triangle.B,
(short)triangle.C
};
MTriplet newMTriplet = new MTriplet(idxArr, minutiae);
int newHash = newMTriplet.GetHashCode();
if (!triplets.ContainsKey(newHash))
{
triplets.Add(newHash, 0);
mtriplets.Add(newMTriplet);
}
}
mtriplets.TrimExcess();
return(new MtripletsFeature(mtriplets, minutiae));
}
/// <summary>
/// Extract features of type <see cref="MtripletsFeature"/> from the specified minutiae.
/// </summary>
/// <param name="minutiae">
/// The list of <see cref="Minutia"/> to extract the features from.
/// </param>
/// <returns>
/// Features of type <see cref="MtripletsFeature"/> extracted from the specified minutiae.
/// </returns>
public MtripletsFeature ExtractFeatures(List <Minutia> minutiae)
{
List <MTriplet> result = new List <MTriplet>();
Dictionary <int, int> triplets = new Dictionary <int, int>();
var nearest = new short[minutiae.Count, neighborsCount];
var distance = new double[minutiae.Count, neighborsCount];
// Initializing distances
for (int i = 0; i < minutiae.Count; i++)
{
for (int j = 0; j < neighborsCount; j++)
{
distance[i, j] = double.MaxValue;
nearest[i, j] = -1;
}
}
// Computing m-triplets
for (short i = 0; i < minutiae.Count; i++)
{
// Updating nearest minutiae
UpdateNearest(minutiae, i, nearest, distance);
// Building m-triplets
for (int j = 0; j < neighborsCount - 1; j++)
{
for (int k = j + 1; k < neighborsCount; k++)
{
if (nearest[i, j] != -1 && nearest[i, k] != -1)
{
if (i == nearest[i, j] || i == nearest[i, k] || nearest[i, j] == nearest[i, k])
{
throw new Exception("Wrong mtp");
}
MTriplet newMTriplet = new MTriplet(new short[] { i, nearest[i, j], nearest[i, k] }, minutiae);
int newHash = newMTriplet.GetHashCode();
if (!triplets.ContainsKey(newHash))
{
triplets.Add(newHash, 0);
result.Add(newMTriplet);
}
}
}
}
}
result.TrimExcess();
return(new MtripletsFeature(result, minutiae));
}
internal List<MtripletPair> FindSimilarMTriplets(MTriplet queryMTp)
{
var result = new List<MtripletPair>();
for (int j = 0; j < MTriplets.Count; j++)
{
MTriplet currMTp = MTriplets[j];
byte[] currOrder;
double currSim = queryMTp.Match(currMTp, out currOrder);
if (currSim > 0)
result.Add(new MtripletPair
{
queryMTp = queryMTp,
templateMTp = currMTp,
matchingValue = currSim,
templateMtiaOrder = currOrder
}
);
}
if (result.Count > 0)
return result;
return null;
}
