private RgbVector[] CalculateInitialColorCentroids()
{
var rand = new Random();
var centroids = new RgbVector[K];
for (int i = 0; i < K; i++)
{
centroids[i] = _superPixels[rand.Next(0, _superPixels.Length)].Data.Centroid.Lab.AsColorXyz()
.AsColorRgb();
}
return(centroids);
}
public void Colors_ShouldRoundtripFromRgbToCielab()
{
// Arrange
var color = Color.Red;
// Act
var colorRgb = new RgbVector(color);
var colorXyz = ColorXyz.FromRgb(colorRgb);
var colorCielab = ColorCielab.FromRgb(colorRgb);
var colorXyzBack = colorCielab.AsColorXyz();
var colorRgbBack = colorXyzBack.AsColorRgb();
// Assert
Assert.Fail();
}
/// <summary>
/// Calculates the initial cluster configuration
/// All clusters have their centroid set, but no pixels assigned
/// </summary>
/// <param name="clusterCount"></param>
/// <returns></returns>
private PixelCluster[] CalculateInitialClusters(int clusterCount)
{
switch (Function)
{
case ClusterRandomFunction.RgbDistance:
// start as a list, so we don't initialize wierd rgbvector defaults
var clusters = new List <PixelCluster>();
for (int i = 0; i < clusterCount; i++)
{
var centroid =
CalculateRandomClusterCentroid((from cluster in clusters select cluster.ColorCentroid).ToArray());
clusters.Add(new PixelCluster {
ColorCentroid = centroid
});
}
return(clusters.ToArray());
break;
case ClusterRandomFunction.HueShift:
// other algorithm
var firstCentroid = CalculateRandomClusterCentroid(new RgbVector[] { });
var centroids = new RgbVector[clusterCount];
// rotate centroid color
centroids[0] = firstCentroid;
for (int i = 1; i < clusterCount; i++)
{
centroids[i] = centroids[i - 1].AsHsvRotated(clusterCount);
}
var clustersHue = from centroid in centroids select new PixelCluster {
ColorCentroid = centroid
};
return(clustersHue.ToArray());
break;
default:
throw new ArgumentOutOfRangeException();
}
}
private double UpdateColorCentroids()
{
var iterator = 0;
var error = 0.0;
// iterate over super pixel pixel collections
foreach (var pixelCollection in CollectPixels())
{
if (pixelCollection.Count == 0)
{
continue;
}
var oldCentroid = _colorCentroids[iterator];
_colorCentroids[iterator] = RgbVector.Mean(pixelCollection.ToArray());
error += oldCentroid.DistanceToSquared(_colorCentroids[iterator]);
iterator++;
}
return(error);
}
