/// <summary>/// 马赛克效果///原理：确定图像的随机位置点和确定马赛克块的大小,然后马赛克块图像覆盖随机点即可./// </summary>/// <param name="m_Iimage"></param>/// <param name="val">分割成val*val像素的小区块</param>        public Image MaSaiKe(Image m_PreImage , int val)        {            Bitmap MyBitmap = new Bitmap(m_PreImage);if (MyBitmap.Equals(null))            {return null;            }int iWidth = MyBitmap.Width;int iHeight = MyBitmap.Height;int stdR , stdG , stdB;            stdR = 0;            stdG = 0;            stdB = 0;            BitmapData srcData = MyBitmap.LockBits(new Rectangle(0 , 0 , iWidth , iHeight) ,            ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb);unsafe            {byte* point = (byte*)srcData.Scan0.ToPointer();for (int i = 0; i < iHeight; i++)                {for (int j = 0; j < iWidth; j++)                    {if (i % val == 0)                        {if (j % val == 0)                            {                                stdR = point[2];                                stdG = point[1];                                stdB = point[0];                            }else                            {                                point[0] = (byte)stdB;                                point[1] = (byte)stdG;                                point[2] = (byte)stdR;                            }                        }else                        {//复制上一行                              byte* pTemp = point - srcData.Stride;                            point[0] = (byte)pTemp[0];                            point[1] = (byte)pTemp[1];                            point[2] = (byte)pTemp[2];                        }                        point += 3;                    }                    point += srcData.Stride - iWidth * 3;                }                MyBitmap.UnlockBits(srcData);            }return MyBitmap;        }