private static int[] GetAlphaCodes(MTriplet mtp)
{
var alpha = new int[3];
for (var i = 0; i < 3; i++)
{
int j;
if (i == 2)
{
j = 0;
}
else
{
j = i + 1;
}
var qMtiai = mtp[i];
var qMtiaj = mtp[j];
double x = qMtiai.X - qMtiaj.X;
double y = qMtiai.Y - qMtiaj.Y;
var angleij = Angle.ComputeAngle(x, y);
var qAlpha = Angle.Difference2Pi(qMtiai.Angle, angleij);
alpha[i] = DiscretizeAngle(qAlpha);
}
return(alpha);
}
internal List <MtripletPair> FindNoRotateAllSimilar(MTriplet queryMTp)
{
// Indexing by MaxDistance
const double dThr = MTriplet.DistanceThreshold;
var d = queryMTp.MaxDistance - dThr;
var iniIdx = BinarySearch(MTriplets, d);
d = queryMTp.MaxDistance + dThr;
var result = new List <MtripletPair>();
for (var j = iniIdx; j < MTriplets.Count && MTriplets[j].MaxDistance <= d; j++)
{
var currMTp = MTriplets[j];
var currSim = queryMTp.NoRotateMatch(currMTp, out var currOrder);
if (currSim > 0)
{
result.Add(new MtripletPair
{
QueryMTp = queryMTp,
TemplateMTp = currMTp,
MatchingValue = currSim,
TemplateMtiaOrder = currOrder
}
);
}
}
return(result.Count > 0 ? result : null);
}
public override MtripletsFeature Extract(Bitmap image)
{
var minutiae = MinutiaeExtractor.ExtractFeatures(image);
var result = new List <MTriplet>();
var triplets = new Dictionary <int, int>();
var nearest = new short[minutiae.Count, NeighborsCount];
var distance = new double[minutiae.Count, NeighborsCount];
// Initializing distances
for (var i = 0; i < minutiae.Count; i++)
{
for (var 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 (var j = 0; j < NeighborsCount - 1; j++)
{
for (var 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");
}
var newMTriplet = new MTriplet(new[] { i, nearest[i, j], nearest[i, k] }, minutiae);
var newHash = newMTriplet.GetHashCode();
if (!triplets.ContainsKey(newHash))
{
triplets.Add(newHash, 0);
result.Add(newMTriplet);
}
}
}
}
}
result.TrimExcess();
return(new MtripletsFeature(result, minutiae));
}
