车道线检测算法经典编程

车道线检测算法经典编程

1. 车道线曲线拟合算法编程

计算经过（50，50），（90，120），（70，200）三点的Catmull_Rom样条曲线。

1. IplImage* img = cvCreateImage(cvSize(300,300), 8, 1);

2. for (int i = 0; i < img->height; ++i)

3. {

4.    for (int j = 0; j < img->width; ++j)  
   

5.    {  
   

6.        ((char *)(img->imageData + img->widthStep * (i)))[j] = 0;  
   

7.    }  
   

8. }

9. CvPoint point0,point1,point2,point3,point4;//3个控制点来做

10. point1.x = 50;

11. point1.y = 50;

12. point2.x = 90;

13. point2.y = 120;

14. point3.x = 70;

15. point3.y = 200;

16. point0.x = point1.x+(point1.x-point2.x);

17. point0.y = point1.y+(point1.y-point2.y);

18. point4.x = point3.x+(point3.x-point2.x);

19. point4.y = point3.y+(point3.y-point2.y);

21. ((char *)(img->imageData + img->widthStep * (point1.y)))[point1.x] = 255;

22. ((char *)(img->imageData + img->widthStep * (point2.y)))[point2.x] = 255;

23. ((char *)(img->imageData + img->widthStep * (point3.y)))[point3.x] = 255;

25. for (int i = 1; i < 500 ; i++) {

27.          float t = (float) i * (1.0f / (float) 500);  
    

28.          float tt = t * t;  
    

29.          float ttt = tt * t;  
    

30.       CvPoint pi;  
    

31.       pi.x = 0.5 * (2*point1.x+(point2.x-point0.x)*t + (2*point0.x-5*point1.x+4*point2.x-point3.x)*tt + (3*point1.x-point0.x-3*point2.x+point3.x)*ttt);  
    

32.          pi.y = 0.5 * (2*point1.y+(point2.y-point0.y)*t + (2*point0.y-5*point1.y+4*point2.y-point3.y)*tt + (3*point1.y-point0.y-3*point2.y+point3.y)*ttt);  
    

33.       ((char *)(img->imageData + img->widthStep * (pi.y)))[pi.x] = 255;  
    

34. }

36. for (int i = 1; i < 500 ; i++) {

38.          float t = (float) i * (1.0f / (float) 500);  
    

39.          float tt = t * t;  
    

40.          float ttt = tt * t;  
    

41.       CvPoint pi;  
    

42.       pi.x = 0.5 * (2*point2.x+(point3.x-point1.x)*t + (2*point1.x-5*point2.x+4*point3.x-point4.x)*tt + (3*point2.x-point1.x-3*point3.x+point4.x)*ttt);  
    

43.          pi.y = 0.5 * (2*point2.y+(point3.y-point1.y)*t + (2*point1.y-5*point2.y+4*point3.y-point4.y)*tt + (3*point2.y-point1.y-3*point3.y+point4.y)*ttt);  
    

44.       ((char *)(img->imageData + img->widthStep * (pi.y)))[pi.x] = 255;  
    

45. }

46. cvShowImage(“scr”, img);

47. cvWaitKey(0);

48. return 0;

49. 检测出Hough空间的曲线，规定如下搜索方法：

霍夫空间中相交的曲线越多，交点表示的线在笛卡尔坐标系对应的点越多。我们在霍夫空间中定义交点的最小阈值来检测线。霍夫变换跟踪了帧中的每个点的霍夫空间交点。如果交点数量超过了阈值就确定一条对应参数 θ 和 d的线。

1>起始搜索点为A点

2>向右搜索，直到退出，退出点为B

3>从B点向左搜索，直到退出

4>起始搜索点回到A点

5>向左搜索，直到退出，退出点为C

6>从C点向右搜索，直到退出

结束

部分代码如下：

向左搜索：

1. CvPoint searchRight(int HoughArea, IplImage hough, CvPoint point, Lines line)

2. {//找当前点的上、右上、右、右下、下

3.    //循环搜索，直到两个方向搜索均无结果，则退出开始下一步判断  
   

4.    CvPoint start;//搜索的初始点  
   

5.    start = point;//先将point作为当前的初始点  
   

6.    int Max = 0;//找局部最大值  
   

7.    CvPoint last = start;//记录上一次最大值，本次搜索排除当前点和上一次点  
   

8.    int mistakes = 0;//引入一个容错因子  
   

9.    //****************************搜索上，右上，右，右下，下*****************************8  
   

10.   while(1)  
    

11.   {  
    

12.       CvPoint temp;  
    

13.       if(start.x >= hough->width-1 || start.y <= 0||start.y >= hough->height-1)//超出搜索范围，退出搜索  
    

14.           break;  
    

15.       //cout << "curve1" << endl;  
    

16.       for(int xx = 0;xx < 2; xx++)  
    

17.       {  
    

18.           for(int yy = -1;yy < 2;yy++)  
    

19.           {  
    

20.               if((xx == 0 && yy == 0)||(start.y + yy == last.y && start.x + xx == last.x))//不包括当前点  
    

21.                   continue;  
    

22.               //cout << HoughArea[start.y + yy][start.x + xx] << endl;  
    

23.               if(HoughArea[start.y + yy][start.x + xx] > Max)  
    

24.               {  
    

25.                   Max = HoughArea[start.y + yy][start.x + xx];  
    

26.                   temp.x = start.x + xx;  
    

27.                   temp.y = start.y + yy;  
    

28.               }   
    

29.           }  
    

30.       }  
    

31.       if(Max > Threshold)  
    

32.       {  
    

33.           //cout << Max << "  ";  
    

34.           mistakes = 0;//容错清零  
    

35.           cout << "find1:"<< Max << endl;  
    

36.           Max = 0;  
    

37.           (*line).houghpoint.push_back(temp);  
    

38.           last = start;//保存上一次最大值  
    

39.           start = temp;//找到的点作为当前点继续搜索  
    

40.           CvScalar s;      
    

41.           s.val[0]=0;  
    

42.           s.val[1]=255;  
    

43.           s.val[2]=0;  
    

44.           //cvSet2D(hough,temp.y,temp.x,s);//set the (i,j) pixel value  
    

45.       }  
    

46.       else if(mistakes <= 5)//容错，三次  
    

47.       {  
    

48.           mistakes++;  
    

49.           Max = 0;  
    

50.           start.x = start.x + 1;  
    

51.       }  
    

52.       else//退出条件  
    

53.           break;//没有找到符合条件的点，退出搜索  
    

54.   }  
    

55.   //*******************************************************************************  
    

56.   CvPoint final;  
    

57.   final.x = start.x - mistakes;  
    

58.   final.y = start.y;  
    

59.   return final;  
    

60. }

61. 导入包含的库文件

#include

#include

#include

#include

#include

using namespace
std;

using namespace cv;

4. 读取图片

   //reading
   image*****

   Mat image;

   image = imread("/home/project1/test1.jpg");

   if(image.empty()){

    cout <<"reading error"<

}

5. 灰度变换

//gray image****

Mat image_gray;

cvtColor(image,image_gray,
CV_BGR2GRAY);

6. canny边缘检测
   

//canny***

Mat image_canny;

Canny(image_gau,
image_canny,100, 200, 3);