/// <summary>
/// Applies min-max normalization to the feature set
/// </summary>
/// <param name="aFeatureList"></param>
/// <returns>The return value contains the normalized Feature set, as well the min and max values used for normaziation</returns>
public static NormalizedFeatures NormalizeFeatures(List <SignatureFeatures> aFeatureList)
{
//Initialize Normalized With list. This will contain the min anf max values used at the normalization of the features
List <NormalizedWith> lNormalizedWith = new List <NormalizedWith>();
for (var i = 0; i < aFeatureList.ElementAt(0).Count; ++i)
{
lNormalizedWith.Add(new NormalizedWith(9999, -9999));
}
for (int i = 0; i < aFeatureList.Count; ++i)
{
SignatureFeatures lFeatures = new SignatureFeatures();
for (int j = 0; j < aFeatureList.ElementAt(i).Count; ++j)
{
var lCurrentFeatureValue = aFeatureList.ElementAt(i).ElementAt(j).Value;
if (lNormalizedWith.ElementAt(j).Min > lCurrentFeatureValue)
{
lNormalizedWith.ElementAt(j).Min = lCurrentFeatureValue;
}
if (lNormalizedWith.ElementAt(j).Max < lCurrentFeatureValue)
{
lNormalizedWith.ElementAt(j).Max = lCurrentFeatureValue;
}
}
}
for (int i = 0; i < aFeatureList.Count; ++i)
{
SignatureFeatures lNormalizedFeatures = new SignatureFeatures();
for (int j = 0; j < aFeatureList.ElementAt(i).Count; ++j)
{
var lCurrentFeature = aFeatureList.ElementAt(i).ElementAt(j);
if (lNormalizedWith.ElementAt(j).Min != lNormalizedWith.ElementAt(j).Max)
{
lNormalizedFeatures[lCurrentFeature.Key] = 2 * ((lCurrentFeature.Value - lNormalizedWith.ElementAt(j).Min) / (lNormalizedWith.ElementAt(j).Max - lNormalizedWith.ElementAt(j).Min)) - 1;
}
else
{
lNormalizedFeatures[lCurrentFeature.Key] = lCurrentFeature.Value;
}
}
aFeatureList.RemoveAt(i);
aFeatureList.Insert(i, lNormalizedFeatures);
}
NormalizedFeatures lNormalized = new NormalizedFeatures(aFeatureList, lNormalizedWith);
return(lNormalized);
}
public Detector(List <SignatureFeatures> aFeatures)
{
mNormalized = FeatureNormalizer.NormalizeFeatures(aFeatures);
foreach (var featureSet in mNormalized.ListOfFeatureSets)
{
foreach (var feature in featureSet)
{
mTemplate[feature.Key] += feature.Value;
}
}
foreach (var feature in mTemplate.ToList())
{
mTemplate[feature.Key] /= mNormalized.ListOfFeatureSets.Count;
}
}
