OpenCV4入门教程132：LSD快速直线检测

使用LSD算法检测图片中所有可能的直线并绘制出来

测试代码1

#include "opencv2/opencv.hpp"

using namespace std;
using namespace cv;

int main()
{
    Mat image = imread("Test.png");
    Mat imgGray;
    cvtColor(image, imgGray, COLOR_BGR2GRAY);

    Ptr<LineSegmentDetector> detector = createLineSegmentDetector();

    vector<Vec4f> lines;
    detector->detect(imgGray,
                     lines);

    Mat result(image.size(),
               CV_8UC3,
               Scalar(0, 0, 0));

    //    detector->drawSegments(result,
    //                           lines);

    // or the following

    Scalar color(0,0,255);
    int thickness = 2;
    for(int i=0; i<lines.size(); i++)
    {
        line(result,
             Point(lines.at(i)[0],
                lines.at(i)[1]),
             Point(lines.at(i)[2],
                lines.at(i)[3]),
             color,
             thickness);
    }

    imshow("image", image);
    imshow("result", result);

    waitKey();

    return 0;
}

效果为

lines

测试代码2

// 功能：代码 5-17 LSD 快速线检测
// 作者：朱伟 zhu1988wei@163.com
// 来源：《OpenCV图像处理编程实例》
// 博客：http://blog.csdn.net/zhuwei1988
// 更新：2016-8-1
// 说明：版权所有，引用或摘录请联系作者，并按照上面格式注明出处，谢谢。// 
#include <iostream>
#include <string>
#include "opencv2/core/core.hpp"
#include "opencv2/core/utility.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
using namespace std;
using namespace cv;
int main()
{

    cv::Mat srcImage = 
      cv::imread("..\\images\\building.jpg", 0);
    if (!srcImage.data)   
       return -1;
    // canny边缘检测
    Canny(srcImage, srcImage, 50, 200, 3);
    // 创建LSD检测类
#if 1
    Ptr<LineSegmentDetector> ls = createLineSegmentDetector(LSD_REFINE_STD);
#else
    Ptr<LineSegmentDetector> ls = createLineSegmentDetector(LSD_REFINE_NONE);
#endif
    double start = double(getTickCount());
    vector<Vec4f> lines_std;
    // 线检测
    ls->detect(srcImage, lines_std);
    double duration_ms = (double(getTickCount()) - start) * 1000 / getTickFrequency();
    std::cout << "It took " << duration_ms << " ms." << std::endl;
    // 绘图线检测结果
    Mat drawnLines(srcImage);
    ls->drawSegments(drawnLines, lines_std);
    cv::imshow("Standard refinement", drawnLines);
    cv::waitKey();
    return 0;
}