/// <summary>
/// Convert a collection of MinutiaRecords to the ISO 19794-2 standard template.
/// NOTE: ISO template stores data as Int8 (X and angle) and Int16 values (Y) so there may
/// be loss of data when casting.
/// </summary>
/// <param name="minutae">The minutae.</param>
/// <returns></returns>
public static byte[] ToIsoTemplate(IEnumerable <MinutiaRecord> minutae)
{
IntegrityCheck.IsNotNull(minutae);
// TODO: Better understand what bytes in IsoTemplate are (Header).
// ISO 19794-2?
List <byte> data = new List <byte>()
{
};
data.AddRange(ToByteArray(HEADER_TOP));
data.Add((byte)ToHeaderMinutiaCountByte(minutae.Count()));
data.AddRange(ToByteArray(HEADER_BOTTOM));
data.Add((byte)(minutae.Count()));
foreach (MinutiaRecord minutia in minutae)
{
data.Add(TypeToByte(minutia.Type));
data.Add((byte)minutia.Position.X);
data.AddRange(YToByte(minutia.Position.Y));
data.Add(AngleToByte(minutia.Angle));
data.Add(QUALITY);
}
data.AddRange(BitConverter.GetBytes(END));
return(data.ToArray());
}
private void CheckSupportedSetting(Setting setting)
{
IntegrityCheck.IsTrue(
SETTINGS_LOOKUP.ContainsKey(setting),
"Validator doesn't recognise setting {0}",
setting);
}
public static IEnumerable <MinutiaRecord> ToMinutae(byte[] isoTemplate)
{
IntegrityCheck.IsNotNull(isoTemplate);
// TODO: IntegrityCheck start is HEADER_TOP
// TODO: IntegrityCheck HEADER_BOTTOM
int headerTopCount = ToByteArray(HEADER_TOP).Count(); // TODO: Make constant
int minutiaCount_1 = ToMinutiaCount(isoTemplate[headerTopCount]);
int headerBottomCount = ToByteArray(HEADER_BOTTOM).Count(); // TODO: Make constant
int minutiaCount_2 = (UInt16)isoTemplate[headerTopCount + 1 + headerBottomCount];
// TODO: IntegrityCheck minutiaCount_1 == minutiaCount_2
int minutiaCount = minutiaCount_1;
int startByte = headerTopCount + 1 + headerBottomCount + 1; // TODO: Make constant
int bytesPerMinutia = 6; // TODO: Make constant
List <MinutiaRecord> minutae = new List <MinutiaRecord>(minutiaCount);
for (int i = 0; i < minutiaCount; i++)
{
MinutiaType type = TypeToMinutiaType(isoTemplate[startByte]);
// TODO: IntegrityCheck type != None
// Get Minutia X-Position
int x = (UInt16)isoTemplate[startByte + 1];
// Get Minutia Y-Position
byte[] yData = new byte[2];
Array.Copy(isoTemplate, startByte + 2, yData, 0, 2);
int y = YToInt(yData);
// Get Minutia angle from the two angle bytes.
double angle = AngleToDouble(isoTemplate[startByte + 4]);
// TODO: IntegrityCheck quality
// Create minutia from data and add to list.
MinutiaRecord minutia = new MinutiaRecord(
new System.Windows.Point(x, y),
angle,
type);
minutae.Add(minutia);
startByte += bytesPerMinutia;
}
// TODO: More assertions
return(minutae);
}
private static byte TypeToByte(MinutiaType type)
{
byte typeData;
switch (type)
{
case MinutiaType.Termination:
typeData = TERMINATION;
break;
case MinutiaType.Bifurication:
typeData = BIFURICATION;
break;
default:
throw IntegrityCheck.FailUnexpectedDefault(type);
}
return(typeData);
}
