C#数字图像处理之图像二值化（彩色变黑白）的方法

//定义图像二值化函数

private static Bitmap PBinary(Bitmap src,int v)

{

 int w = src.Width;

 int h = src.Height;

 Bitmap dstBitmap = new Bitmap(src.Width ,src.Height ,System .Drawing .Imaging .PixelFormat .Format24bppRgb );

 System.Drawing.Imaging.BitmapData srcData = src.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

 System.Drawing.Imaging.BitmapData dstData = dstBitmap.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

 unsafe

 {

  byte* pIn = (byte*)srcData.Scan0.ToPointer();

  byte* pOut = (byte*)dstData.Scan0.ToPointer();

  byte* p;

  int stride = srcData.Stride;

  int r, g, b;

  for (int y = 0; y < h; y++)

  {

  for (int x = 0; x < w; x++)

  {

   p = pIn;

   r = p[2];

   g = p[1];

   b = p[0];

   pOut [0]=pOut [1]=pOut [2]=(byte)(((byte)(0.2125 * r + 0.7154 * g + 0.0721 * b) >= v)

   ? 255 : 0);

   pIn += 3;

   pOut += 3;

  }

  pIn += srcData.Stride - w * 3;

  pOut += srcData.Stride - w * 3;

  }

  src.UnlockBits(srcData );

  dstBitmap.UnlockBits(dstData );

  return dstBitmap;

 }

}