public override TemplateBuilder Import(byte[] template)
{
TemplateBuilder builder = new TemplateBuilder();
MemoryStream stream = new MemoryStream(template);
BinaryReader reader = new BinaryReader(stream, Encoding.UTF8);
// 4B magic
for (int i = 0; i < Magic.Length; ++i)
{
AssertException.Check(reader.ReadByte() == Magic[i]);
}
// 1B version (current = 2)
byte version = reader.ReadByte();
AssertException.Check(version >= 1 && version <= 2);
// 2B total length (including magic)
reader.ReadInt16();
if (version >= 2)
{
// 2B original DPI (since version 2)
builder.OriginalDpi = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 2B original width (since version 2)
builder.OriginalWidth = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 2B original height (since version 2)
builder.OriginalHeight = IPAddress.NetworkToHostOrder(reader.ReadInt16());
}
// 2B minutia count
int minutiaCount = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// N*6B minutia records
for (int i = 0; i < minutiaCount; ++i)
{
TemplateBuilder.Minutia minutia = new TemplateBuilder.Minutia();
// 2B position X
minutia.Position.X = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 2B position Y
minutia.Position.Y = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 1B direction
minutia.Direction = reader.ReadByte();
// 1B type
minutia.Type = (TemplateBuilder.MinutiaType)reader.ReadByte();
AssertException.Check(Enum.IsDefined(typeof(TemplateBuilder.MinutiaType), minutia.Type));
builder.Minutiae.Add(minutia);
}
return(builder);
}
public ParameterValue GetDifference(ParameterSet original)
{
ParameterSet diff = GetDifferences(original);
ParameterValue[] all = diff.AllParameters;
AssertException.Check(all.Length <= 1);
return(all[0]);
}
void TraceRidges(BinaryMap binary, Dictionary <Point, SkeletonBuilder.Minutia> minutiaePoints)
{
Dictionary <Point, SkeletonBuilder.Ridge> leads = new Dictionary <Point, SkeletonBuilder.Ridge>();
foreach (Point minutiaPoint in minutiaePoints.Keys)
{
foreach (Point startRelative in Neighborhood.CornerNeighbors)
{
Point start = Calc.Add(minutiaPoint, startRelative);
if (binary.GetBitSafe(start, false) && !minutiaePoints.ContainsKey(start) && !leads.ContainsKey(start))
{
SkeletonBuilder.Ridge ridge = new SkeletonBuilder.Ridge();
ridge.Points.Add(minutiaPoint);
ridge.Points.Add(start);
Point previous = minutiaPoint;
Point current = start;
do
{
Point next = new Point();
foreach (Point nextRelative in Neighborhood.CornerNeighbors)
{
next = Calc.Add(current, nextRelative);
if (binary.GetBitSafe(next, false) && next != previous)
{
break;
}
}
AssertException.Check(next != new Point());
previous = current;
current = next;
ridge.Points.Add(current);
} while (!minutiaePoints.ContainsKey(current));
Point end = current;
ridge.Start = minutiaePoints[minutiaPoint];
ridge.End = minutiaePoints[end];
leads[ridge.Points[1]] = ridge;
leads[ridge.Reversed.Points[1]] = ridge;
}
}
}
}
// References:
// http://www.italdata-roma.com/PDF/Norme%20ISO-IEC%20Minutiae%20Data%20Format%2019794-2.pdf
// https://biolab.csr.unibo.it/fvcongoing/UI/Form/Download.aspx (ISO section, sample ZIP, ISOTemplate.pdf)
//
// Format (all numbers are big-endian):
// 4B magic "FMR\0"
// 4B version (ignored, set to " 20\0"
// 4B total length (including header)
// 2B rubbish (zeroed)
// 2B image size in pixels X
// 2B image size in pixels Y
// 2B rubbish (pixels per cm X, set to 196 = 500dpi)
// 2B rubbish (pixels per cm Y, set to 196 = 500dpi)
// 1B rubbish (number of fingerprints, set to 1)
// 1B rubbish (zeroed)
// 1B rubbish (finger position, zeroed)
// 1B rubbish (zeroed)
// 1B rubbish (fingerprint quality, set to 100)
// 1B minutia count
// N*6B minutiae
// 2B minutia position X in pixels
// 2b (upper) minutia type (01 ending, 10 bifurcation, 00 other (considered ending))
// 2B minutia position Y in pixels (upper 2b ignored, zeroed)
// 1B direction, compatible with SourceAFIS angles
// 1B quality (ignored, zeroed)
// 2B rubbish (extra data length, zeroed)
// N*1B rubbish (extra data)
public override byte[] Export(TemplateBuilder builder)
{
MemoryStream stream = new MemoryStream();
BinaryWriter writer = new BinaryWriter(stream, Encoding.UTF8);
checked
{
// 4B magic "FMR\0"
writer.Write("FMR\0".ToCharArray());
// 4B version (ignored, set to " 20\0"
writer.Write(" 20\0".ToCharArray());
// 4B total length (including header, will be updated later)
writer.Write(0);
// 2B rubbish (zeroed)
writer.Write((short)0);
// 2B image size in pixels X
writer.Write(IPAddress.HostToNetworkOrder((short)builder.StandardDpiWidth));
// 2B image size in pixels Y
writer.Write(IPAddress.HostToNetworkOrder((short)builder.StandardDpiHeight));
// 2B rubbish (pixels per cm X, set to 196 = 500dpi)
writer.Write(IPAddress.HostToNetworkOrder((short)196));
// 2B rubbish (pixels per cm Y, set to 196 = 500dpi)
writer.Write(IPAddress.HostToNetworkOrder((short)196));
// 1B rubbish (number of fingerprints, set to 1)
writer.Write((byte)1);
// 1B rubbish (zeroed)
writer.Write((byte)0);
// 1B rubbish (finger position, zeroed)
writer.Write((byte)0);
// 1B rubbish (zeroed)
writer.Write((byte)0);
// 1B rubbish (fingerprint quality, set to 100)
writer.Write((byte)100);
// 1B minutia count
writer.Write((byte)builder.Minutiae.Count);
// N*6B minutiae
foreach (var minutia in builder.Minutiae)
{
// 2B minutia position X in pixels
// 2b (upper) minutia type (01 ending, 10 bifurcation, 00 other (considered ending))
int x = minutia.Position.X;
AssertException.Check(x <= 0x3fff, "X position is out of range");
int type = minutia.Type == TemplateBuilder.MinutiaType.Extremidade ? 0x4000 : 0x8000;
writer.Write(IPAddress.HostToNetworkOrder(unchecked ((short)(x | type))));
// 2B minutia position Y in pixels (upper 2b ignored, zeroed)
int y = builder.StandardDpiHeight - minutia.Position.Y - 1;
AssertException.Check(y <= 0x3fff, "Y position is out of range");
writer.Write(IPAddress.HostToNetworkOrder((short)y));
// 1B direction, compatible with SourceAFIS angles
writer.Write(minutia.Direction);
// 1B quality (ignored, zeroed)
writer.Write((byte)0);
}
// 2B rubbish (extra data length, zeroed)
// N*1B rubbish (extra data)
writer.Write((short)0);
}
writer.Close();
// update length
byte[] template = stream.ToArray();
BitConverter.GetBytes(IPAddress.HostToNetworkOrder(template.Length)).CopyTo(template, 8);
return(template);
}
public override TemplateBuilder Import(byte[] template)
{
TemplateBuilder builder = new TemplateBuilder();
builder.OriginalDpi = 500;
MemoryStream stream = new MemoryStream(template);
BinaryReader reader = new BinaryReader(stream, Encoding.UTF8);
// 4B magic "FMR\0"
AssertException.Check(new String(reader.ReadChars(4)) == "FMR\0", "This is not an ISO template.");
// 4B version (ignored, set to " 20\0"
reader.ReadChars(4);
// 4B total length (including header)
AssertException.Check(IPAddress.NetworkToHostOrder(reader.ReadInt32()) == template.Length, "Invalid template length.");
// 2B rubbish (zeroed)
reader.ReadInt16();
// 2B image size in pixels X
builder.StandardDpiWidth = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 2B image size in pixels Y
builder.StandardDpiHeight = IPAddress.NetworkToHostOrder(reader.ReadInt16());
// 2B rubbish (pixels per cm X, set to 196 = 500dpi)
reader.ReadInt16();
// 2B rubbish (pixels per cm Y, set to 196 = 500dpi)
reader.ReadInt16();
// 1B rubbish (number of fingerprints, set to 1)
AssertException.Check(reader.ReadByte() == 1, "Only single-fingerprint ISO templates are supported.");
// 1B rubbish (zeroed)
reader.ReadByte();
// 1B rubbish (finger position, zeroed)
reader.ReadByte();
// 1B rubbish (zeroed)
reader.ReadByte();
// 1B rubbish (fingerprint quality, set to 100)
reader.ReadByte();
// 1B minutia count
int minutiaCount = reader.ReadByte();
// N*6B minutiae
for (int i = 0; i < minutiaCount; ++i)
{
TemplateBuilder.Minutia minutia = new TemplateBuilder.Minutia();
// 2B minutia position X in pixels
// 2b (upper) minutia type (01 ending, 10 bifurcation, 00 other (considered ending))
ushort xPacked = (ushort)IPAddress.NetworkToHostOrder(reader.ReadInt16());
minutia.Position.X = xPacked & (ushort)0x3fff;
minutia.Type = (xPacked & (ushort)0xc000) == 0x8000 ? TemplateBuilder.MinutiaType.Bifurcação : TemplateBuilder.MinutiaType.Extremidade;
// 2B minutia position Y in pixels (upper 2b ignored, zeroed)
minutia.Position.Y = builder.StandardDpiHeight - 1 - ((ushort)IPAddress.NetworkToHostOrder(reader.ReadInt16()) & (ushort)0x3fff);
// 1B direction, compatible with SourceAFIS angles
minutia.Direction = reader.ReadByte();
// 1B quality (ignored, zeroed)
reader.ReadByte();
builder.Minutiae.Add(minutia);
}
// 2B rubbish (extra data length, zeroed)
// N*1B rubbish (extra data)
return(builder);
}
