public Bitmap hough_line(Bitmap bmpobj, int cross_num)
{
Bitmap I_out = bmpobj;
int x = bmpobj.Width;
int y = bmpobj.Height;
for (int ii = 0; ii < 10; ii++)
{
int rho_max = (int)Math.Floor(Math.Sqrt(x * x + y * y)) + 1; //由原图数组坐标算出ρ最大值,并取整数部分加1
//此值作为ρ,θ坐标系ρ最大值
int[,] accarray = new int[rho_max, 180]; //定义ρ,θ坐标系的数组,初值为0。
//θ的最大值,180度
double[] Theta = new double[180];
//定义θ数组,确定θ取值范围
double i = 0;
for (int index = 0; index < 180; index++)
{
Theta[index] = i;
i += Math.PI / 180;
}
double rho;
int rho_int;
for (int n = 0; n < x; n++)
{
for (int m = 0; m < y; m++)
{
Color pixel = bmpobj.GetPixel(n, m);
if (pixel.R == 255)
{
for (int k = 0; k < 180; k++)
{
//将θ值代入hough变换方程,求ρ值
rho = (m * Math.Cos(Theta[k])) + (n * Math.Sin(Theta[k]));
//将ρ值与ρ最大值的和的一半作为ρ的坐标值(数组坐标),这样做是为了防止ρ值出现负数
rho_int = (int)Math.Round(rho / 2 + rho_max / 2);
//在ρθ坐标(数组)中标识点,即计数累加
accarray[rho_int, k] = accarray[rho_int, k] + 1;
}
}
}
}
//=======利用hough变换提取直线======
//寻找100个像素以上的直线在hough变换后形成的点
const int max_line = 100;
int[] case_accarray_n = new int[max_line];
int[] case_accarray_m = new int[max_line];
int K = 0; //存储数组计数器
for (int rho_n = 0; rho_n < rho_max; rho_n++) //在hough变换后的数组中搜索
{
for (int theta_m = 0; theta_m < 180; theta_m++)
{
if (accarray[rho_n, theta_m] >= cross_num && K < max_line) //设定直线的最小值
{
case_accarray_n[K] = rho_n; //存储搜索出的数组下标
case_accarray_m[K] = theta_m;
K = K + 1;
}
}
}
//把这些点构成的直线提取出来,输出图像数组为I_out
//I_out=ones(x,y).*255;
for (int n = 0; n < x; n++)
{
for (int m = 0; m < y; m++)
{
//首先设置为白色
Color pixel = bmpobj.GetPixel(n, m);
if (pixel.R == 255)
{
for (int k = 0; k < 180; k++)
{
rho = (m * Math.Cos(Theta[k])) + (n * Math.Sin(Theta[k]));
rho_int = (int)Math.Round(rho / 2 + rho_max / 2);
//如果正在计算的点属于100像素以上点,则把它提取出来
for (int a = 0; a < K - 1; a++)
{
//if rho_int==case_accarray_n(a) && k==case_accarray_m(a)%%%==gai==%%% k==case_accarray_m(a)&rho_int==case_accarray_n(a)
if (rho_int == case_accarray_n[a] && k == case_accarray_m[a])
I_out.SetPixel(n, m, Color.Black);
}
}
}
}
}
}
return I_out;
} public Bitmap hough_line(Bitmap bmpobj, int c