snippet.cs

// 中值滤波优化理
// 仅对灰度处于dgGrayValue~dgGrayValue2的点进行处
public static Bitmap medianFilter(Bitmap bmp, int dgGrayValue, int dgGrayValue2)
{
    Bitmap bmpobj = new Bitmap(bmp);
    int x, y;
    byte[] p = new byte[9]; //最小处理窗口3*3
    byte s;
    int i, j;
    for (y = 1; y < bmpobj.Height - 1; y++) //排除边框
    {
        for (x = 1; x < bmpobj.Width - 1; x++)
        {
            if (!(bmpobj.GetPixel(x, y).R >= dgGrayValue && bmpobj.GetPixel(x, y).R <= dgGrayValue2))
                continue;
            //取9个点的值
            p[0] = bmpobj.GetPixel(x - 1, y - 1).R;
            p[1][1] = bmpobj.GetPixel(x, y - 1).R;
            p[2][2] = bmpobj.GetPixel(x + 1, y - 1).R;
            p[3] = bmpobj.GetPixel(x - 1, y).R;
            p[4] = bmpobj.GetPixel(x, y).R;
            p[5] = bmpobj.GetPixel(x + 1, y).R;
            p[6] = bmpobj.GetPixel(x - 1, y + 1).R;
            p[7] = bmpobj.GetPixel(x, y + 1).R;
            p[8] = bmpobj.GetPixel(x + 1, y + 1).R;
            //计算中值
            for (j = 0; j < 5; j++)
            {
                for (i = j + 1; i < 9; i++)
                {
                    if (p[j] > p[i])
                    {
                        s = p[j];
                        p[j] = p[i];
                        p[i] = s;
                    }
                }
            }
            bmpobj.SetPixel(x, y, Color.FromArgb(p[4], p[4], p[4])); //中值 p4
        }
    }
    return bmpobj;
}