C# 簡單的圖像邊緣提取

博主做的很簡單，大家看一看就好了......

用到的算法是robert算子，這是一種比較簡單的算法：

f(x,y)=sqrt((g(x,y)-g(x+1,y+1))^2+(g(x+1,y)-g(x,y+1))^2)

博主一共寫了三段代碼，第一段是邊緣提取，第二段是線條加粗，第三段是原圖和邊緣圖重合，三段代碼可以放在一起，但為了看得清晰我就把他們分開了。

簡單粗暴直接上代碼！

PRivate void Image_Test()        {            if (this.pBox.Image != null)            {                               int Height = this.pBox.Image.Height;                int Width = this.pBox.Image.Width;                Bitmap bitmap = new Bitmap(Width, Height, PixelFormat.Format24bppRgb);                Bitmap MyBitmap = (Bitmap)this.pBox.Image;                BitmapData oldData = MyBitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb); //原圖                BitmapData newData = bitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);  //新圖即邊緣圖                unsafe                {                       //首先第一段代碼是提取邊緣，邊緣置為黑色，其他部分置為白色                    byte* pin_1 = (byte*)(oldData.Scan0.ToPointer());                    byte* pin_2 = pin_1 + (oldData.Stride);                                     byte* pout = (byte*)(newData.Scan0.ToPointer());                    for (int y = 0; y < oldData.Height - 1; y++)                    {                        for (int x = 0; x < oldData.Width; x++)                        {                            //使用robert算子                            double b = System.Math.Sqrt(((double)pin_1[0] - (double)(pin_2[0] + 3)) * ((double)pin_1[0] - (double)(pin_2[0] + 3)) + ((double)(pin_1[0] + 3) - (double)pin_2[0]) * ((double)(pin_1[0] + 3) - (double)pin_2[0]));                            double g = System.Math.Sqrt(((double)pin_1[1] - (double)(pin_2[1] + 3)) * ((double)pin_1[1] - (double)(pin_2[1] + 3)) + ((double)(pin_1[1] + 3) - (double)pin_2[1]) * ((double)(pin_1[1] + 3) - (double)pin_2[1]));                            double r = System.Math.Sqrt(((double)pin_1[2] - (double)(pin_2[2] + 3)) * ((double)pin_1[2] - (double)(pin_2[2] + 3)) + ((double)(pin_1[2] + 3) - (double)pin_2[2]) * ((double)(pin_1[2] + 3) - (double)pin_2[2]));                            double bgr = b + g + r;//博主一直在糾結要不要除以3，感覺沒差，選閾值的時候調整一下就好了- -                                                        if (bgr > 80) //閾值，超過閾值判定為邊緣（選取適當的閾值）                            {                                b = 0;                                g = 0;                                r = 0;                            }                            else                            {                                b = 255;                                g = 255;                                r = 255;                            }                            pout[0] = (byte)(b);                            pout[1] = (byte)(g);                            pout[2] = (byte)(r);                            pin_1 = pin_1 + 3;                            pin_2 = pin_2 + 3;                            pout = pout + 3;                        }                        pin_1 += oldData.Stride - oldData.Width * 3;                        pin_2 += oldData.Stride - oldData.Width * 3;                        pout += newData.Stride - newData.Width * 3;                    }                    //這里博主加粗了一下線條- -，不喜歡的同學可以刪了這段代碼                    byte* pin_5 = (byte*)(newData.Scan0.ToPointer());                                        for (int y = 0; y < oldData.Height - 1; y++)                    {                        for (int x = 3; x < oldData.Width; x++)                        {                            if(pin_5[0]==0&&pin_5[1]==0&&pin_5[2]==0)                            {                                pin_5[-3] = 0;                                pin_5[-2] = 0;                                pin_5[-1] = 0;      //邊緣點的前一個像素點置為黑色（注意一定要是遍歷過的像素點）                                                                                }                            pin_5 += 3;                                                    }                        pin_5 += newData.Stride - newData.Width * 3;                                         }                                        //這段代碼是把原圖和邊緣圖重合                    byte* pin_3= (byte*)(oldData.Scan0.ToPointer());                    byte* pin_4 = (byte*)(newData.Scan0.ToPointer());                    for (int y = 0; y < oldData.Height - 1; y++)                    {                        for (int x = 0; x < oldData.Width; x++)                        {                            if (pin_4[0] == 255 && pin_4[1]==255 && pin_4[2]==255)                             {                                pin_4[0] = pin_3[0];                                pin_4[1] = pin_3[1];                                pin_4[2] = pin_3[2];                            }                            pin_3 += 3;                            pin_4 += 3;                        }                        pin_3 += oldData.Stride - oldData.Width * 3;                        pin_4 += newData.Stride - newData.Width * 3;                    }                    //......                    bitmap.UnlockBits(newData);                    MyBitmap.UnlockBits(oldData);                    this.pBox.Image = bitmap;                }            }                    }

例子1：

例子2：