需要用到一個圓弧檢測的程式，苦於網上沒有C++版的，自己根據MATLAB函式寫了一個，自己感覺沒什麼問題，編譯也可以通過，但結果就是很奇怪，求各位大咖幫忙，新手，小白一個。。。。

void hough_circle(IplImage *BW,double step_r,double step_angle,double r_min,double r_max,double p)
{
	//[m,n] = size(BW);
	int m=BW->width,n=BW->height;
	int size_r = (int)((r_max-r_min)/step_r)+1;
	int size_angle = (int)(2*pi/step_angle);
	//hough_space = zeros(m,n,size_r);
	int l=m*n*size_r;
	int *hough_space=new int [l];
	for(int i=0;i<l;i++)
		hough_space[i]=0;
 
//[rows,cols] = find(BW);
	typedef struct Str
	{
	int row;
	int col;
	}Str;
	int SIZE=BW->height*BW->width;
	Str *location=new Str [SIZE];
	int ecount=0;//計數，統計白點
	for (int i = 0; i < BW->height; i++)
     {
         for (int j = 0; j < BW->width; j++)
         {
            char  pixel = *(BW->imageData + i*BW->widthStep+j);
			if(pixel==255)
			{
				location[ecount].row=i;
				location[ecount].col=j;
				ecount++;
			}
		 }
	}

//ecount = size(rows);
 
/*% Hough變換
% 將影象空間(x,y)對應到引數空間(a,b,r)
% a = x-r*cos(angle)
% b = y-r*sin(angle)*/
/*for i=1:ecount
    for r=1:size_r
        for k=1:size_angle
            a = round(rows(i)-(r_min+(r-1)*step_r)*cos(k*step_angle));
            b = round(cols(i)-(r_min+(r-1)*step_r)*sin(k*step_angle));
            if(a>0&a<=m&b>0&b<=n)
                hough_space(a,b,r) = hough_space(a,b,r)+1;
            end
        end
    end
end*/
 int a=0,b=0;
 for(int i=0;i<ecount;i++)
	 for(int r=1;r<=size_r;r++)
		 for(int k=1;k<=size_angle;k++)
		 {
			a = (int)(location[i].row-(r_min+(r-1)*step_r)*cos(k*step_angle));
            b = (int)(location[i].col-(r_min+(r-1)*step_r)*sin(k*step_angle));
			if((a>0)&(a<=m)&(b>0)&(b<=n))
				hough_space[r*m*n+a*m+b]++;
		 }

 
// 搜尋超過閾值的聚集點
/*max_para = max(max(max(hough_space)));
index = find(hough_space>=max_para*p);
length = size(index);
hough_circle=zeros(m,n);*/
int max_para=hough_space[0];
for(int i=1;i<l;i++)
{
	max_para=max_para>=hough_space[i]?max_para:hough_space[i];
}
int thre=max_para*p;
int par1[LEN],par2[LEN],par3[LEN];
for (int j=0;j<LEN;j++)
{
par1[j]=0,par2[j]=0,par3[j]=0;
}
int length=0;//超過閾值的點個數
for(int i=1;i<l;i++)
	if(hough_space[i]>=thre)
	{
		par3[length]=i/(m*n)+1;
		par2[length]=(i%(m*n))/m+1;
		par1[length]=(i%(m*n))%m+1;
		length++;
	}
int size_h=m*n;
int *hough_circle=new int [size_h];
for (int i=0;i<size_h;i++)
	hough_circle[i]=0;



/*for i=1:ecount
    for k=1:length
        par3 = floor(index(k)/(m*n))+1;
        par2 = floor((index(k)-(par3-1)*(m*n))/m)+1;
        par1 = index(k)-(par3-1)*(m*n)-(par2-1)*m;
        if((rows(i)-par1)^2+(cols(i)-par2)^2<(r_min+(par3-1)*step_r)^2+5&...
                (rows(i)-par1)^2+(cols(i)-par2)^2>(r_min+(par3-1)*step_r)^2-5)
            hough_circle(rows(i),cols(i)) = 1;
        end
    end
end*/

//par3是半徑，par1和par2是要檢測的圓的座標。
//index(k)在hough_space中的三維位置(par1,par2,par3)
for(int i=0;i<ecount;i++)
    for (int k=0;k<length;k++)
        if(((location[i].row-par1[k])^2+(location[i].col-par2[k])^2<(r_min+(par3[k]-1)*step_r)^2+5)&((location[i].row-par1[k])^2+(location[i].col-par2[k])^2>(r_min+(par3[k]-1)*step_r)^2-5))
            hough_circle[location[i].row*m+location[i].col] = 1;

 
//列印結果 
cout<<"圓點座標      "<<"半徑     "<<endl;
for (int k=0;k<length;k++)
    {
		par3[k] = r_min+(par3[k]-1)*step_r;
        cout<<par1[k]<<"  "<<par2[k]<<"   "<<par3[k]<<endl;
}
}