C#实现图像锐化的方法

//定义图像锐化函数private static Bitmap Sharpen(Bitmap a,double v){  int w = a.Width; int h = a.Height; try {  Bitmap dstBitmap = new Bitmap(w, h, 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;  for (int y = 0; y < h; y++)  {   for (int x = 0; x < w; x++)   {   //边缘八个点像素不变   if (x == 0 || x == w - 1 || y == 0 || y == h - 1)   {    pOut[0] = pIn[0];    pOut[1] = pIn[1];    pOut[2] = pIn[2];   }   else   {    int r0, r1, r2, r3, r4, r5, r6, r7, r8;    int g1, g2, g3, g4, g5, g6, g7, g8, g0;    int b1, b2, b3, b4, b5, b6, b7, b8, b0;    double vR, vG, vB;    //左上    p = pIn - stride - 3;    r1 = p[2];    g1 = p[1];    b1 = p[0];    //正上    p = pIn - stride;    r2 = p[2];    g2 = p[1];    b2 = p[0];    //右上    p = pIn - stride + 3;    r3 = p[2];    g3 = p[1];    b3 = p[0];    //左    p = pIn - 3;    r4 = p[2];    g4 = p[1];    b4 = p[0];    //右    p = pIn + 3;    r5 = p[2];    g5 = p[1];    b5 = p[0];    //左下    p = pIn + stride - 3;    r6 = p[2];    g6 = p[1];    b6 = p[0];    //正下    p = pIn + stride;    r7 = p[2];    g7 = p[1];    b7 = p[0];    // 右下     p = pIn + stride + 3;    r8 = p[2];    g8 = p[1];    b8 = p[0];    //中心点    p = pIn;    r0 = p[2];    g0 = p[1];    b0 = p[0];    vR = (double)r0 - (double)(r1 + r2 + r3 + r4 + r5 + r6 + r7 + r8) / 8;    vG = (double)g0 - (double)(g1 + g2 + g3 + g4 + g5 + g6 + g7 + g8) / 8;    vB = (double)b0 - (double)(b1 + b2 + b3 + b4 + b5 + b6 + b7 + b8) / 8;    vR = r0 + vR * v;    vG = g0 + vG * v;    vB = b0 + vB * v;    if (vR > 0)    {    vR = Math.Min(255, vR);    }    else    {    vR = Math.Max(0, vR);    }    if (vG > 0)    {    vG = Math.Min(255, vG);    }    else    {    vG = Math.Max(0, vG);    }    if (vB > 0)    {    vB = Math.Min(255, vB);    }    else    {    vB = Math.Max(0, vB);    }    pOut[0] = (byte)vB;    pOut[1] = (byte)vG;    pOut[2] = (byte)vR;   }   pIn += 3;   pOut += 3;   }   pIn += srcData.Stride - w * 3;   pOut += srcData.Stride - w * 3;  }  }  a.UnlockBits(srcData);  dstBitmap.UnlockBits(dstData);  return dstBitmap; } catch {  return null; }}