C#实现图像反色的方法

//定义图像反色函数private static Bitmap PContray (Bitmap a){ int w = a.Width; int h = a.Height; Bitmap dstBitmap = new Bitmap(a.Width, a.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb); System.Drawing.Imaging.BitmapData srcData = a.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[2] = (byte)(255 - r);   pOut[1] = (byte)(255 - g);   pOut[0] = (byte)(255 - b);   pIn += 3;   pOut += 3;   }   pIn += srcData.Stride - w * 3;   pOut += srcData.Stride - w * 3;  }  a.UnlockBits(srcData);  dstBitmap.UnlockBits(dstData);  return dstBitmap; }}