private void Noise(BitmapModel inputPointer, BitmapModel outputPointer, int sigma)
{
var random = Randoms.Create(DateTime.Now.Millisecond + Thread.CurrentThread.ManagedThreadId, RandomType.FastestDouble);
for (var i = 0; i < inputPointer.Length; i++)
{
var a = random.NextDouble();
var b = random.NextDouble();
var noise = (float)(sigma * Math.Sqrt(-2.0 * Math.Log(a)) * Math.Cos(2.0 * Math.PI * b));
outputPointer.Data[i] = inputPointer.Data[i] + noise;
}
}
public (SKBitmap, FilteringStatsModel) MakeNoisy(SKBitmap input, int sigma)
{
var inputChannels = BitmapModel.Create(input);
var noisyChannels = BitmapModel.Create(inputChannels.Width, inputChannels.Height, inputChannels.ColorType, inputChannels.AlphaType);
var watch = Stopwatch.StartNew();
this.Noise(inputChannels, noisyChannels, sigma);
watch.Stop();
var noisy = noisyChannels.ToBitmap();
var stats = BitmapHelpers.CalculateStats(input, noisy, watch.ElapsedMilliseconds);
return(noisy, stats);
}
