Matlab实现基于Hough变换的直线检测算法
时间: 2024-06-09 09:05:23 浏览: 16
Hough变换是一种常用的图像处理技术,可以用于检测直线等几何形状。下面是基于Hough变换的直线检测算法的Matlab实现:
1. 读入图像并进行边缘检测
```matlab
img = imread('image.jpg');
gray = rgb2gray(img);
edge_img = edge(gray, 'canny');
```
2. 设置Hough变换参数
```matlab
theta_range = -90:0.5:89.5;
[num_rows, num_cols] = size(edge_img);
rho_max = hypot(num_rows, num_cols);
rho_range = -rho_max:0.5:rho_max;
num_thetas = length(theta_range);
num_rhos = length(rho_range);
hough_space = zeros(num_rhos, num_thetas);
```
3. 构建Hough空间
```matlab
for i = 1:num_rows
for j = 1:num_cols
if edge_img(i, j) > 0
for theta_index = 1:num_thetas
theta = theta_range(theta_index) * pi / 180;
rho = i * cos(theta) + j * sin(theta);
rho_index = round(rho / 0.5 + num_rhos / 2);
hough_space(rho_index, theta_index) = hough_space(rho_index, theta_index) + 1;
end
end
end
end
```
4. 找到Hough空间的峰值
```matlab
num_peaks = 10;
peak_threshold = 0.5 * max(hough_space(:));
peaks = [];
for i = 1:num_peaks
[rho_index, theta_index] = find(hough_space >= peak_threshold, 1);
if isempty(rho_index) || isempty(theta_index)
break;
end
peaks = [peaks; rho_index, theta_index];
hough_space(rho_index, theta_index) = 0;
end
```
5. 将Hough空间的峰值转换为直线方程
```matlab
lines = [];
for i = 1:size(peaks, 1)
rho = rho_range(peaks(i, 1));
theta = theta_range(peaks(i, 2)) * pi / 180;
a = -tan(theta);
b = 1;
c = rho / sin(theta);
lines = [lines; a, b, c];
end
```
6. 在原图上绘制直线
```matlab
figure, imshow(img);
hold on;
for i = 1:size(lines, 1)
a = lines(i, 1);
b = lines(i, 2);
c = lines(i, 3);
x0 = 1;
y0 = - (a * x0 + c) / b;
x1 = num_cols;
y1 = - (a * x1 + c) / b;
plot([x0, x1], [y0, y1], 'LineWidth', 2, 'Color', 'r');
end
hold off;
```
以上就是基于Hough变换的直线检测算法的Matlab实现步骤,希望对你有所帮助。