C#数字图象处理之图像灰度化 C#数字图象处理之图像灰度化方法

//定义图像灰度化函数
private static Bitmap PGray(Bitmap src)
{
  int w = src.Width;
  int h = src.Height;
//构建与原图像大小一样的模版图像
  Bitmap dstBitmap = new Bitmap(src.Width, src.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
//将原图像存入内存
  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];
//调用图像灰度化公式
 pOut[0] = pOut[1] = pOut[2] = (byte)(b * 0.114 + g * 0.587 + r * 0.299);  
 pIn += 3;
 pOut += 3;
   }
   pIn += srcData.Stride - w * 3;
   pOut += srcData.Stride - w * 3;
 }
 src.UnlockBits(srcData);
 dstBitmap.UnlockBits(dstData);
 return dstBitmap;
  }
}