private static void BuildPalette(IDictionary <RGBColor, RGBColor> palette)
{
var colors = new double[palette.Keys.Count][];
Parallel.ForEach(palette.Keys.Select((color, index) => (color, index)), tuple => {
colors[tuple.index] = tuple.color.CopyTo(new double[3]);
});
var kmeans = new KMeans(MaxColor);
var clusters = kmeans.Learn(colors);
var reduce = clusters.Centroids.Select(RGBColor.CopyFrom).ToArray();
Parallel.ForEach(colors, color => {
var normal = RGBColor.CopyFrom(color);
var idx = clusters.Decide(color);
palette[normal] = reduce[idx];
});
}
