public static double GaussNoise(double u, double d)
{
double u1, u2, z, x;
//Random ram = new Random();
if (d <= 0)
{
return(u);
}
u1 = (new Random(ToolFunctions.GetRandomSeed())).NextDouble();
u2 = (new Random(ToolFunctions.GetRandomSeed())).NextDouble();
z = Math.Sqrt(-2 * Math.Log(u1)) * Math.Sin(2 * Math.PI * u2);
x = u + d * z;
return(x);
}
public static void AddPepperSalt(Bitmap srcBmp, double Pa, double Pb, out Bitmap dstBmp)
{
// Bitmap pic = (Bitmap)Bitmap.FromFile(filename, false);
dstBmp = srcBmp;
Bitmap tmpBmp = (Bitmap)dstBmp.Clone();
double P = Pb / (1 - Pa);//程序要,为了得到一个概率Pb事件
int width = dstBmp.Width;
int height = dstBmp.Height;
Random rand = new Random(ToolFunctions.GetRandomSeed());
Rectangle rt = new Rectangle(0, 0, srcBmp.Width, srcBmp.Height);
BitmapData bmpData = tmpBmp.LockBits(rt, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
Task t1 = new Task(() =>
{
unsafe
{
for (int i = 0; i < bmpData.Height / 2; i++)
{
byte *ptr = (byte *)bmpData.Scan0 + i * bmpData.Stride;
for (int j = 0; j < bmpData.Width / 2; j++)
{
double probility = rand.NextDouble();
rand.NextDouble();
if (probility == 0)
{
rand = new Random(ToolFunctions.GetRandomSeed());
//probility = rand.NextDouble();
}
if (probility < Pa)
{
//noiseC = Color.White;//有Pa概率 噪声设为最大值
*(ptr + j * 3) = 255; //B
*(ptr + j * 3 + 1) = 255; //G
*(ptr + j * 3 + 2) = 255; //R
//Console.WriteLine("probility:"+probility);
}
else
{
double temp = rand.NextDouble();
if (temp < P) //有1 - Pa的几率到达这里，再乘以 P ，刚好等于Pb
{
*(ptr + j * 3) = 0; //B
*(ptr + j * 3 + 1) = 0; //G
*(ptr + j * 3 + 2) = 0; //R
}
}
}
}
}
//tmpBmp.UnlockBits(bmpData);
});
Task t2 = new Task(() =>
{
//BitmapData bmpData = tmpBmp.LockBits(rt, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
unsafe
{
for (int i = bmpData.Height / 2; i < bmpData.Height; i++)
{
byte *ptr = (byte *)bmpData.Scan0 + i * bmpData.Stride;
for (int j = 0; j < bmpData.Width / 2; j++)
{
double probility = rand.NextDouble();
if (probility == 0)
{
rand = new Random(ToolFunctions.GetRandomSeed());
//probility = rand.NextDouble();
}
if (probility < Pa)
{
//noiseC = Color.White;//有Pa概率 噪声设为最大值
*(ptr + j * 3) = 255; //B
*(ptr + j * 3 + 1) = 255; //G
*(ptr + j * 3 + 2) = 255; //R
//Console.WriteLine("probility:"+probility);
}
else
{
double temp = rand.NextDouble();
if (temp < P) //有1 - Pa的几率到达这里，再乘以 P ，刚好等于Pb
{
*(ptr + j * 3) = 0; //B
*(ptr + j * 3 + 1) = 0; //G
*(ptr + j * 3 + 2) = 0; //R
}
}
}
}
}
//tmpBmp.UnlockBits(bmpData);
});
Task t3 = new Task(() =>
{
//BitmapData bmpData = tmpBmp.LockBits(rt, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
unsafe
{
for (int i = 0; i < bmpData.Height / 2; i++)
{
byte *ptr = (byte *)bmpData.Scan0 + i * bmpData.Stride;
for (int j = bmpData.Width / 2; j < bmpData.Width; j++)
{
double probility = rand.NextDouble();
if (probility == 0)
{
rand = new Random(ToolFunctions.GetRandomSeed());
//probility = rand.NextDouble();
}
if (probility < Pa)
{
//noiseC = Color.White;//有Pa概率 噪声设为最大值
*(ptr + j * 3) = 255; //B
*(ptr + j * 3 + 1) = 255; //G
*(ptr + j * 3 + 2) = 255; //R
//Console.WriteLine("probility:"+probility);
}
else
{
double temp = rand.NextDouble();
if (temp < P) //有1 - Pa的几率到达这里，再乘以 P ，刚好等于Pb
{
*(ptr + j * 3) = 0; //B
*(ptr + j * 3 + 1) = 0; //G
*(ptr + j * 3 + 2) = 0; //R
}
}
}
}
}
//tmpBmp.UnlockBits(bmpData);
});
Task t4 = new Task(() =>
{
//BitmapData bmpData = tmpBmp.LockBits(rt, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
unsafe
{
int i = bmpData.Height / 2;
for (; i < bmpData.Height; i++)
{
byte *ptr = (byte *)bmpData.Scan0 + i * bmpData.Stride;
for (int j = bmpData.Width / 2; j < bmpData.Width; j++)
{
double probility = rand.NextDouble();
if (probility == 0)
{
rand = new Random(ToolFunctions.GetRandomSeed());
//probility = rand.NextDouble();
}
if (probility < Pa)
{
//noiseC = Color.White;//有Pa概率 噪声设为最大值
*(ptr + j * 3) = 255; //B
*(ptr + j * 3 + 1) = 255; //G
*(ptr + j * 3 + 2) = 255; //R
//Console.WriteLine("probility:"+probility);
}
else
{
double temp = rand.NextDouble();
if (temp < P) //有1 - Pa的几率到达这里，再乘以 P ，刚好等于Pb
{
*(ptr + j * 3) = 0; //B
*(ptr + j * 3 + 1) = 0; //G
*(ptr + j * 3 + 2) = 0; //R
}
}
}
}
Console.WriteLine("over t4:" + i);
}
//tmpBmp.UnlockBits(bmpData);
});
t1.Start();
t2.Start();
t3.Start();
t4.Start();
//t1.Wait();
//t2.Wait();
Task.WaitAll(t1, t2, t3, t4);
tmpBmp.UnlockBits(bmpData);
dstBmp = tmpBmp;
//for (int i = 0; i < height; i++)
//{
// for (int j = 0; j < width; j++)
// {
// Color noiseC = dstBmp.GetPixel(j, i);
// double probility = rand.NextDouble();
// if (probility < Pa)
// {
// noiseC = Color.White;//有Pa概率 噪声设为最大值
// }
// else
// {
// double temp = rand.NextDouble();
// if (temp < P)//有1 - Pa的几率到达这里，再乘以 P ，刚好等于Pb
// noiseC = Color.Black;
// }
// Color color = noiseC;
// dstBmp.SetPixel(j, i, color);
// }
//}
}