FingerprintTemplate(MutableTemplate mutable)
{
Size = mutable.Size;
var minutiae =
from m in mutable.Minutiae
orderby((m.Position.X * Prime) + m.Position.Y) * Prime, m.Position.X, m.Position.Y, m.Direction, m.Type
select new ImmutableMinutia(m);
Minutiae = minutiae.ToArray();
// https://sourceafis.machinezoo.com/transparency/shuffled-minutiae
FingerprintTransparency.Current.Log("shuffled-minutiae", () => Mutable());
Edges = NeighborEdge.BuildTable(Minutiae);
}
static List <MatchingPair> FindMatchingPairs(NeighborEdge[] probeStar, NeighborEdge[] candidateStar)
{
byte complementaryAngleError = Angle.Complementary(FingerprintMatcher.MaxAngleError);
var results = new List <MatchingPair>();
Range range = new Range();
for (int candidateIndex = 0; candidateIndex < candidateStar.Length; ++candidateIndex)
{
NeighborEdge candidateEdge = candidateStar[candidateIndex];
while (range.Begin < probeStar.Length && probeStar[range.Begin].Edge.Length < candidateEdge.Edge.Length - FingerprintMatcher.MaxDistanceError)
{
++range.Begin;
}
if (range.End < range.Begin)
{
range.End = range.Begin;
}
while (range.End < probeStar.Length && probeStar[range.End].Edge.Length <= candidateEdge.Edge.Length + FingerprintMatcher.MaxDistanceError)
{
++range.End;
}
for (int probeIndex = range.Begin; probeIndex < range.End; ++probeIndex)
{
var probeEdge = probeStar[probeIndex];
byte referenceDiff = Angle.Difference(probeEdge.Edge.ReferenceAngle, candidateEdge.Edge.ReferenceAngle);
if (referenceDiff <= FingerprintMatcher.MaxAngleError || referenceDiff >= complementaryAngleError)
{
byte neighborDiff = Angle.Difference(probeEdge.Edge.NeighborAngle, candidateEdge.Edge.NeighborAngle);
if (neighborDiff <= FingerprintMatcher.MaxAngleError || neighborDiff >= complementaryAngleError)
{
results.Add(new MatchingPair()
{
Pair = new MinutiaPair()
{
Probe = probeEdge.Neighbor,
Candidate = candidateEdge.Neighbor
},
Distance = candidateEdge.Edge.Length
});
}
}
}
}
return(results);
}
public static NeighborEdge[][] BuildTable(ImmutableMinutia[] minutiae)
{
var edges = new NeighborEdge[minutiae.Length][];
var star = new List <NeighborEdge>();
var allSqDistances = new int[minutiae.Length];
for (int reference = 0; reference < edges.Length; ++reference)
{
var referencePosition = minutiae[reference].Position;
int maxSqDistance = Int32.MaxValue;
if (minutiae.Length - 1 > Parameters.EdgeTableNeighbors)
{
for (int neighbor = 0; neighbor < minutiae.Length; ++neighbor)
{
allSqDistances[neighbor] = (referencePosition - minutiae[neighbor].Position).LengthSq;
}
Array.Sort(allSqDistances);
maxSqDistance = allSqDistances[Parameters.EdgeTableNeighbors];
}
for (int neighbor = 0; neighbor < minutiae.Length; ++neighbor)
{
if (neighbor != reference && (referencePosition - minutiae[neighbor].Position).LengthSq <= maxSqDistance)
{
star.Add(new NeighborEdge(minutiae, reference, neighbor));
}
}
star.Sort((a, b) =>
{
int lengthCmp = a.Length.CompareTo(b.Length);
if (lengthCmp != 0)
{
return(lengthCmp);
}
return(a.Neighbor.CompareTo(b.Neighbor));
});
while (star.Count > Parameters.EdgeTableNeighbors)
{
star.RemoveAt(star.Count - 1);
}
edges[reference] = star.ToArray();
star.Clear();
}
// https://sourceafis.machinezoo.com/transparency/edge-table
FingerprintTransparency.Current.Log("edge-table", edges);
return(edges);
}
void BuildEdgeTable()
{
const int maxDistance = 490;
const int maxNeighbors = 9;
EdgeTable = new NeighborEdge[Minutiae.Count][];
var edges = new List <NeighborEdge>();
var allSqDistances = new int[Minutiae.Count];
for (int reference = 0; reference < EdgeTable.Length; ++reference)
{
Point referencePosition = Minutiae[reference].Position;
int sqMaxDistance = MathEx.Sq(maxDistance);
if (Minutiae.Count - 1 > maxNeighbors)
{
for (int neighbor = 0; neighbor < Minutiae.Count; ++neighbor)
{
allSqDistances[neighbor] = (referencePosition - Minutiae[neighbor].Position).SqLength;
}
Array.Sort(allSqDistances);
sqMaxDistance = allSqDistances[maxNeighbors];
}
for (int neighbor = 0; neighbor < Minutiae.Count; ++neighbor)
{
if (neighbor != reference && (referencePosition - Minutiae[neighbor].Position).SqLength <= sqMaxDistance)
{
NeighborEdge record = new NeighborEdge();
record.Edge = new EdgeShape(this, reference, neighbor);
record.Neighbor = neighbor;
edges.Add(record);
}
}
edges.Sort(NeighborEdgeComparer.Instance);
if (edges.Count > maxNeighbors)
{
edges.RemoveRange(maxNeighbors, edges.Count - maxNeighbors);
}
EdgeTable[reference] = edges.ToArray();
edges.Clear();
}
}
static List<MatchingPair> FindMatchingPairs(NeighborEdge[] probeStar, NeighborEdge[] candidateStar)
{
byte complementaryAngleError = Angle.Complementary(FingerprintMatcher.MaxAngleError);
var results = new List<MatchingPair>();
Range range = new Range();
for (int candidateIndex = 0; candidateIndex < candidateStar.Length; ++candidateIndex)
{
NeighborEdge candidateEdge = candidateStar[candidateIndex];
while (range.Begin < probeStar.Length && probeStar[range.Begin].Edge.Length < candidateEdge.Edge.Length - FingerprintMatcher.MaxDistanceError)
++range.Begin;
if (range.End < range.Begin)
range.End = range.Begin;
while (range.End < probeStar.Length && probeStar[range.End].Edge.Length <= candidateEdge.Edge.Length + FingerprintMatcher.MaxDistanceError)
++range.End;
for (int probeIndex = range.Begin; probeIndex < range.End; ++probeIndex)
{
var probeEdge = probeStar[probeIndex];
byte referenceDiff = Angle.Difference(probeEdge.Edge.ReferenceAngle, candidateEdge.Edge.ReferenceAngle);
if (referenceDiff <= FingerprintMatcher.MaxAngleError || referenceDiff >= complementaryAngleError)
{
byte neighborDiff = Angle.Difference(probeEdge.Edge.NeighborAngle, candidateEdge.Edge.NeighborAngle);
if (neighborDiff <= FingerprintMatcher.MaxAngleError || neighborDiff >= complementaryAngleError)
results.Add(new MatchingPair()
{
Pair = new MinutiaPair()
{
Probe = probeEdge.Neighbor,
Candidate = candidateEdge.Neighbor
},
Distance = candidateEdge.Edge.Length
});
}
}
}
return results;
}