C#实现图像锐化的方法

本文实例讲述了C#实现图像锐化的方法。分享给大家供大家参考。具体如下：

//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;
}
}

希望本文所述对大家的C#程序设计有所帮助。