C# 指针操作图像 细化处理

        /// <summary>
        /// 图形细化
        /// </summary>
        /// <param name="srcImg"></param>
        /// <returns></returns>
        public unsafe Bitmap ToThinner(Bitmap srcImg)
        {
            int iw = srcImg.Width;
            int ih = srcImg.Height;
            bool bModified;     //二值图像修改标志
            bool bCondition1;   //细化条件1标志
            bool bCondition2;   //细化条件2标志
            bool bCondition3;   //细化条件3标志
            bool bCondition4;   //细化条件4标志
            int nCount;
            //5X5像素块
            byte[,] neighbour = new byte[, ];
            //新建临时存储图像
            Bitmap NImg = new Bitmap(iw, ih, srcImg.PixelFormat);
            bModified = true;
            //细化修改标志, 用作循环条件
            BitmapData dstData = srcImg.LockBits(new Rectangle(, , iw, ih), ImageLockMode.ReadWrite, srcImg.PixelFormat);
            byte* data = (byte*)(dstData.Scan0);
            //将图像转换为0,1二值得图像;
            int step = dstData.Stride;
            for (int i = ; i < dstData.Height; i++)
            {
                for (int j = ; j < dstData.Width * ; j += )
                {
                    if (data[i * step + j] > )
                        //如果是白线条，只要将0改成1，将1改成0
                        data[i * step + j]
                            = data[i * step + j + ]
                            = data[i * step + j + ]
                            = ;
                    else
                        data[i * step + j]
                            = data[i * step + j + ]
                            = data[i * step + j + ]
                            = ;
                }
            }

            BitmapData dstData1 = NImg.LockBits(new Rectangle(, , iw, ih), ImageLockMode.ReadWrite, NImg.PixelFormat);
            byte* data1 = (byte*)(dstData1.Scan0);
            int step1 = dstData1.Stride;
            //细化循环开始
            while (bModified)
            {
                bModified = false;
                //初始化临时二值图像NImg
                for (int i = ; i < dstData1.Height; i++)
                {
                    for (int j = ; j < dstData1.Width * ; j++)
                    {
                        data1[i * step1 + j] = ;
                    }
                }
                for (int i = ; i < ih - ; i++)
                {
                    for (int j = ; j < iw *  - ; j += )
                    {
                        bCondition1 = false;
                        bCondition2 = false;
                        bCondition3 = false;
                        bCondition4 = false;
                        if (data[i * step + j] == )
                            //若图像的当前点为白色，则跳过
                            continue;
                        for (int k = ; k < ; k++)
                        {
                            //取以当前点为中心的5X5块
                            for (int l = ; l < ; l++)
                            {
                                //1代表黑色, 0代表白色
                                //neighbour[k, l] = bw[i + k - 2, j + l - 2];
                                //neighbour[k, l] = data[(i + k - 2) * step + (j + l - 2)];
                                neighbour[k, l] = data[(i + k - ) * step + (j + l *  - )];
                            }
                        }
                        //(1)判断条件2<=n(p)<=6
                        nCount = neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ];
                        if (nCount >=  && nCount <= )
                            bCondition1 = true;
                        else
                        {
                            data1[i * step1 + j] = ;
                            continue;
                            //跳过, 加快速度
                        }
                        //(2)判断s(p)=1
                        nCount = ;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (neighbour[, ] ==  && neighbour[, ] == )
                            nCount++;
                        if (nCount == )
                            bCondition2 = true;
                        else
                        {
                            data1[i * step1 + j] = ;
                            continue;
                        }
                        //(3)判断p0*p2*p4=0 or s(p2)!=1
                        if (neighbour[, ] * neighbour[, ] * neighbour[, ] == )
                            bCondition3 = true;
                        else
                        {
                            nCount = ;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (nCount != )
                                //s(p2)!=1
                                bCondition3 = true;
                            else
                            {
                                data1[i * step1 + j] = ;
                                continue;
                            }
                        }
                        //(4)判断p2*p4*p6=0 or s(p4)!=1
                        if (neighbour[, ] * neighbour[, ] * neighbour[, ] == )
                            bCondition4 = true;
                        else
                        {
                            nCount = ;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (neighbour[, ] ==  && neighbour[, ] == )
                                nCount++;
                            if (nCount != )//s(p4)!=1
                                bCondition4 = true;
                        }
                        if (bCondition1 && bCondition2 && bCondition3 && bCondition4)
                        {
                            data1[i * step1 + j] = ;
                            bModified = true;
                        }
                        else
                        {
                            data1[i * step1 + j] = ;
                        }
                    }
                }
                // 将细化了的临时图像bw_tem[w,h]copy到bw[w,h],完成一次细化
                for (int i = ; i < ih - ; i++)
                    for (int j = ; j < iw *  - ; j++)
                        data[i * step + j] = data1[i * step1 + j];
            }
            for (int i = ; i < ih - ; i++)
            {
                for (int j = ; j < iw *  - ; j += )
                {
                    if (data[i * step + j] == )

                        data[i * step + j]
                            = data[i * step + j + ]
                            = data[i * step + j + ]
                            = ;

                    else

                        data[i * step + j]
                            = data[i * step + j + ]
                            = data[i * step + j + ]
                            = ;

                }
            }
            srcImg.UnlockBits(dstData);
            NImg.UnlockBits(dstData1);
            return (srcImg);
        }