/// <summary>
/// Calculate the LOD dictionary based on the Bitmap Source and requested LOD in the constructor.
///
/// The colour returned (the byte) is dependent on the CalculateBestColor method, which can be
/// overridden to weight specific colour keys.
/// </summary>
/// <returns></returns>
public virtual Dictionary <Int32Rect, byte> CalculateLod()
{
var initialRect = new Int32Rect(0, 0, BitmapSource.PixelHeight, BitmapSource.PixelHeight);
// Subdivide the rectangle
var outputList = new List <Int32Rect>();
initialRect.Subdivide(LevelOfDetail, outputList);
var outputDictionary = new ConcurrentDictionary <Int32Rect, byte>();
if (BitmapSource.CanFreeze)
{
BitmapSource.Freeze();
}
Parallel.ForEach(outputList, (element) =>
{
Dictionary <byte, int> colorsWithFrequency = BitmapSource.GetDistinctColors(element);
byte bestColor = CalculateBestColor(element, colorsWithFrequency);
outputDictionary[element] = bestColor;
});
return(outputDictionary.ToDictionary(c => c.Key, c => c.Value));
}
