/// <summary>
/// Este metodo intenta recuperar los simbolos de la base de datos
/// correspondiente a una imagen.
/// </summary>
/// <param name="image">
/// La imagen cuyos simbolos asociados queremos encontrar.
/// </param>
/// <returns>
/// Los simbolos que se puedieron asociar con la imagen.
/// </returns>
public override List <MathSymbol> Match(MathTextBitmap image)
{
List <MathSymbol> res = new List <MathSymbol>();
FloatBitmap processedImage = image.LastProcessedImage;
TristateCheckVector vector = CreateVector(processedImage);
// We have this image vector, now we will compare with the stored ones.
foreach (TristateCheckVector storedVector in symbolsDict)
{
// We consider a threshold.
int threshold = (int)((storedVector.Length - storedVector.DontCares) * epsilon);
// If the distance is below the threshold, we consider it valid.
if (storedVector.Distance(vector) <= threshold)
{
foreach (MathSymbol symbol in storedVector.Symbols)
{
// We don't want duplicated symbols.
if (!res.Contains(symbol))
{
res.Add(symbol);
}
}
string msg =
String.Format("Distancia({0}, {1}) <= {2}",
vector.ToString(),
storedVector.ToString(),
threshold);
msg += "\nSe añadieron los símbolos almacenados.";
StepDoneInvoker(new StepDoneArgs(msg));
}
else
{
string msg = String.Format("Distancia({0}, {1}) > {2}",
vector.ToString(),
storedVector.ToString(),
threshold);
StepDoneInvoker(new StepDoneArgs(msg));
}
}
return(res);
}
/// <summary>
/// Creates a <see cref="TristateCheckVector"/> instance for a given
/// <c>FloatBitmap</c> object.
/// </summary>
/// <param name="image">
/// A <see cref="FloatBitmap"/> for which the vector is created.
/// </param>
/// <returns>
/// The <see cref="TristateCheckVector"/> for the image.
/// </returns>
private TristateCheckVector CreateVector(FloatBitmap image)
{
// We create the receptors list.
if (receptors == null)
{
receptors = Receptor.GenerateList(40);
}
TristateCheckVector vector = new TristateCheckVector();
TristateValue checkValue;
foreach (Receptor receptor in receptors)
{
checkValue =
receptor.CheckBressard(image)?
TristateValue.True:TristateValue.False;
vector.Values.Add(checkValue);
StepDoneArgs args =
new StepDoneArgs(String.Format("Comprobando receptor {0}: {1}",
String.Format("({0}, {1}) -> ({2}, {3})",
receptor.X0, receptor.Y0,
receptor.X1, receptor.Y1),
checkValue));
StepDoneInvoker(args);
Thread.Sleep(20);
}
foreach (BinaryCharacteristic characteristic in characteristics)
{
checkValue =
characteristic.Apply(image)?
TristateValue.True
: TristateValue.False;
vector.Values.Add(checkValue);
StepDoneArgs args =
new StepDoneArgs(String.Format("Comprobando característica {0}: {1}",
characteristic.GetType().ToString(),
checkValue));
StepDoneInvoker(args);
Thread.Sleep(20);
}
return(vector);
}
/// <summary>
/// This method is used to add new symbols to the database.
/// </summary>
/// <param name="bitmap">
/// The image containing the symbol.
/// </param>
/// <param name="symbol">
/// The symbol contained in the image.
/// </param>
public override bool Learn(MathTextBitmap bitmap, MathSymbol symbol)
{
FloatBitmap processedBitmap = bitmap.LastProcessedImage;
TristateCheckVector newVector = CreateVector(processedBitmap);
TristateCheckVector found = null;
foreach (TristateCheckVector vector in symbolsDict)
{
if (vector.Symbols.Contains(symbol))
{
found = vector;
break;
}
}
if (found == null)
{
// The symbol wasnt present in the database.
newVector.Symbols.Add(symbol);
symbolsDict.Add(newVector);
}
else
{
// The symbol is present, we may have to retrain the database.
if (newVector.Equals(found))
{
// It's the same one, so there is a conflict.
return(false);
}
else
{
// We have to find the differnces, and change them to
// don't care values.
for (int i = 0; i < found.Length; i++)
{
if (found[i] != TristateValue.DontCare &&
found[i] != newVector[i])
{
// If the value is different from what we had learned,
// then we make the vector more general in that point.
found[i] = TristateValue.DontCare;
}
}
}
}
return(true);
}
