//----------------------------- For prediction -------------------------------------//
/// <summary>
/// Predicts the class of a unknown face using a linear discriminant. It works in the original DIM space.
/// </summary>
/// <param name="Face"> Face to be categorized</param>
/// <returns></returns>
public int PredictClassUsingDiscriminant(ATTFace Face)
{
double[] x = Face.ImageVectorTransformed; //We like to work on the PCA Space for classification
IMatrix SigmaInv = this.SW.Inverse;
int ID = -1;
double maxValue = 0.0;
int i = 0;
foreach (KeyValuePair <int, FaceClass> entry in FacesByClass)
{
double[] ui = entry.Value.MeanOfClass;
double pi = entry.Value.ProbabilityOfBelonging;
double discriminant = Math.Abs(CalculateDiscriminantValue(x, ui, pi, SigmaInv));
Console.WriteLine("Discriminant for Class (" + entry.Value.ID + ")" + " = " + discriminant);
if (i == 0)
{
maxValue = discriminant;
}
i++;
if (discriminant < maxValue)
{
ID = entry.Value.ID;
maxValue = discriminant;
}
}
return(ID);
}
private void btnTestImage_Click(object sender, EventArgs e)
{
if (LDAClassifier == null)
{
MessageBox.Show("Classifier not trained. Please press Train!");
}
else
{
OpenFileDialog Dialog = new OpenFileDialog();
Dialog.Filter = "jpeg files (*.jpg)|*.jpg|(*.gif)|gif||";
if (DialogResult.OK == Dialog.ShowDialog())
{
ATTFace face = DataUnit.GetATTFace(Dialog.FileName);
double[] projectedPCA = PCAClassifier.ComputeProjection(face.ImageVector); // Do not forget to project in PCA Space
face.ImageVectorTransformed = projectedPCA;
Bitmap TestBitmap = face.getImagesAsBmp();
ShowImage(TestBitmap, picTestImage);
FileInfo fileInfo = new FileInfo(Dialog.FileName);
lblTestImage.Text = fileInfo.Name;
int guessID = LDAClassifier.PredictClassInProjectedSpace(face);
MessageBox.Show("Guessed Class: " + guessID);
List <ATTFace> BestFaces = LDAClassifier.FacesByClass[guessID].FacesInClass; //By default, we print the images in the class
DisplayBestMatches(BestFaces);
}
}
}
public Object Clone()
{
ATTFace Copy = new ATTFace();
Copy.Closeness = this.Closeness;
Copy.ImageVector = this.ImageVector;
Copy.ImageVectorTransformed = this.ImageVectorTransformed;
Copy.personID = this.personID;
Copy.FileName = this.FileName;
return(Copy);
}
/// <summary>
/// Computes the projection onto the LDABase (W)
/// </summary>
/// <param name="Face"></param>
/// <returns></returns>
private double[] ComputeLDAProjection(ATTFace Face)
{
double[] x = Face.ImageVectorTransformed;
double[] projected = new double[WMatrix.Columns]; //C-1 Dimensions
for (int j = 0; j < this.WMatrix.Columns; j++)
{
double temp = 0.0;
for (int i = 0; i < WMatrix.Rows; i++)
{
temp += x[i] * WMatrix[i, j];
}
projected[j] = temp;
}
return(projected);
}
/// <summary>
/// Read files and generates a training dataset
/// </summary>
/// <param name="trainingPath"> Directory Path of where Training data is located</param>
/// <returns> </returns>
public static List <ATTFace> GetTrainingData(String trainingPath)
{
List <ATTFace> Faces = new List <ATTFace>();
DirectoryInfo di = new DirectoryInfo(trainingPath);
FileInfo[] files = di.GetFiles("*.jpg");
foreach (FileInfo fileInfo in files)
{
String fileName = fileInfo.Name;
String[] parts = fileName.Split('_');
int personID = int.Parse(parts[0].Substring(1, parts[0].Length - 1));
Bitmap faceBitmap = new Bitmap(trainingPath + "\\" + fileName);
double[] ImageAsArray = BitmapToArray(faceBitmap);
ATTFace face = new ATTFace(fileName, personID, ImageAsArray);
Faces.Add(face);
}
return(Faces);
}
public int CompareTo(Object obj)
{
if (obj == null)
{
return(1);
}
ATTFace OtherFace = obj as ATTFace;
if (OtherFace != null)
{
return(this.CompareTo(OtherFace.Closeness));
}
else
{
throw new ArgumentException("Object is not an ATTFace");
}
}
/// <summary>
/// Allows capabilities of comparing vectors in the projected space and give an ID to the unknown data.
/// </summary>
/// <param name="Face"> Face to be categorized</param>
/// <param name="Decision"> Decision type. Either KNN or ClossestNeighbor</param>
/// <param name="neighborNumber">How many neighbors to consider if using KNN</param>
/// <returns></returns>
public int PredictClassInProjectedSpace(ATTFace Face, DecisionType Decision = DecisionType.ClossestNeighbor, int neighborNumber = 3)
{
double[] projected = ComputeLDAProjection(Face);
int ID = -1;
foreach (ATTFace ReferenceFace in FaceList)
{
double[] y = ReferenceFace.LDAProjection;
double dist = EuclideanDistance(y, projected);
ReferenceFace.Closeness = dist;
}
FaceList.Sort();
if (Decision == DecisionType.ClossestNeighbor)
{
ID = FaceList[0].personID;
}
else if (Decision == DecisionType.KNN)
{
IDictionary <int, int> Tally = new Dictionary <int, int>();
int maxVotes = 0;
ID = -1;
for (int i = 0; i < neighborNumber; i++)
{
ATTFace Person = FaceList[i];
if (Tally.ContainsKey(Person.personID))
{
Tally[Person.personID]++;
if (Tally[Person.personID] > maxVotes)
{
//To be here, a personID needs at leats two votes
maxVotes = Tally[Person.personID];
ID = Person.personID;
}
}
else
{
Tally.Add(Person.personID, 1);
}
}
}
return(ID);
}
/// <summary>
/// Finds the Best Match(es) as a list, and provides a guessed Person ID.
/// </summary>
/// <param name="imageAsVector"> Image of the person to be classified.</param>
/// <param name="decisionType"> Either ClossestNeighbor or KKN</param>
/// <param name="measureType"> Either Euclidean or Projection. Determines which measurement is to be used.</param>
/// <param name="BestFaces"> List of ATTFaces passed by reference. Must be empty. BestMatches added to the list if onlyID = false</param>
/// <param name="guessID">int passed by reference. The class of the person images guessed by PCA.</param>
/// <param name="neighborNumber"> How many neighbors to use for KNN. Default is 3</param>
/// <param name="numberFaces">How many Best Matches to add to BestFaces. Default is 6</param>
/// <param name="onlyID"> Whether ONLY the class of the person is of interest. If the BestFaces are also of interest, set to false/</param>
public void FindBestMatch(double[] imageAsVector, DecisionType decisionType, ClossenessMeasure measureType, ref List <ATTFace> BestFaces, ref int guessID, int neighborNumber = 3, int numberFaces = 6, bool onlyID = true)
{
double[] meanAdjusted = SubstractArrays(imageAsVector, MeanFaceAsArray);
double[] projectedImage = ComputeProjection(meanAdjusted);
foreach (ATTFace Person in DataSet)
{
double similarity;
if (measureType == ClossenessMeasure.Euclidean)
{
similarity = EuclideanDistance(Person.ImageVectorTransformed, projectedImage);
Person.Closeness = similarity;
}
else if (measureType == ClossenessMeasure.Projection)
{
similarity = DotProduct(Person.ImageVectorTransformed, projectedImage);
Person.Closeness = -similarity; //A maximization is transformed to a minimization by putting a -
}
else
{
throw new ArgumentException("ClosenessMeasure is not supported!");
}
}
DataSet.Sort();
// ------------------------------------------ Retrieving best guess ------------------------------//
if (decisionType == DecisionType.ClossestNeighbor)
{
guessID = DataSet[0].personID;
}
else if (decisionType == DecisionType.KNN)
{
IDictionary <int, int> Tally = new Dictionary <int, int>();
int maxVotes = 0;
guessID = -1;
for (int i = 0; i < neighborNumber; i++)
{
ATTFace Person = DataSet[i];
if (Tally.ContainsKey(Person.personID))
{
Tally[Person.personID]++;
if (Tally[Person.personID] > maxVotes)
{
//To be here, a personID needs at leats two votes
maxVotes = Tally[Person.personID];
guessID = Person.personID;
}
}
else
{
Tally.Add(Person.personID, 1);
}
}
}
else
{
throw new ArgumentException("DecisionType not valid!");
}
// ---------------------------- Populating the list onlyID = False ----------------//
if (!onlyID)
{
for (int i = 0; i < numberFaces; i++)
{
BestFaces.Add((ATTFace)DataSet[i].Clone());
}
}
}
