/// <summary>
/// Resets ColourInfo.Frequency fields to the number of times that colour appears in the image.
/// If Image has N pixels, and ColourMap has M colours, total time = M + Nlog(M) ~= N
/// </summary>
public void UpdateColourMapFrequency()
{
if (mOutput == null || ColourMap == null)
{
return;
}
ColourMap.ClearFrequencies(); // M
Bitmap b = mOutput;
for (int x = 0; x < b.Width; x++) // this loop iterates N times
{
for (int y = 0; y < b.Height; y++)
{
Color c = b.GetPixel(x, y);
ColourMap.Colours[c].Frequency++; // Dictionary access is log(M)?
}
}
}
