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如何在opencv中畫線

[英]how to draw line in opencv

您好,每位ace都有問題這是我的代碼,誰能教我如何在中心的視頻中繪制一條直線? 以及如何減少視頻中的綠線,因為我想找到消失點。

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>e
using namespace cv;
using namespace std;
Point2f center(0,0);
Point2f computeIntersect(Vec4i a, Vec4i b)

{
    int x1 = a[0], y1 = a[1], x2 = a[2], y2 = a[3], x3 = b[0], y3 = b[1], x4 = b[2], y4 = b[3];
    float denom;

    if (float d = ((float)(x1 - x2) * (y3 - y4)) - ((y1 - y2) * (x3 - x4)))
    {
            Point2f pt;
            pt.x = ((x1 * y2 - y1 * x2) * (x3 - x4) - (x1 - x2) * (x3 * y4 - y3 * x4)) / d;
            pt.y = ((x1 * y2 - y1 * x2) * (y3 - y4) - (y1 - y2) * (x3 * y4 - y3 * x4)) / d;
            return pt;
    }
    else
            return Point2f(-1, -1);


}
void sortCorners(std::vector<Point2f>& corners, Point2f center)

{
    std::vector<Point2f> top, bot;





    for (int i = 0; i < corners.size(); i++)
    {
            if (corners[i].y < center.y)
                    top.push_back(corners[i]);
            else
                    bot.push_back(corners[i]);
    }

    Point2f tl = top[0].x > top[1].x ? top[1] : top[0];
    Point2f tr = top[0].x > top[1].x ? top[0] : top[1];
    Point2f bl = bot[0].x > bot[1].x ? bot[1] : bot[0];
    Point2f br = bot[0].x > bot[1].x ? bot[0] : bot[1];

    corners.clear();
    corners.push_back(tl);
    corners.push_back(tr);
    corners.push_back(br);
    corners.push_back(bl);
}
Mat src;
int main()

{







VideoCapture cap("C://pic/way.mp4");
while ( cap.isOpened() )
{
cap >> src;





    //Mat src = imread("D:\\11.jpg");
    if (src.empty())
            return -1;

    Mat bw;
    cvtColor(src, bw, CV_BGR2GRAY);
    blur(bw, bw, Size(3, 3));
    Canny(bw, bw, 150, 100, 3);

    std::vector<Vec4i> lines;
    HoughLinesP(bw, lines, 1, CV_PI/180, 70, 30, 10);

    // Expand the lines
    for (int i = 0; i < lines.size(); i++)
    {
            Vec4i v = lines[i];
            lines[i][0] = 0;
            lines[i][1] = ((float)v[1] - v[3]) / (v[0] - v[2]) * -v[0] + v[1]; 
            lines[i][2] = src.cols; 
            lines[i][3] = ((float)v[1] - v[3]) / (v[0] - v[2]) * (src.cols - v[2]) + v[3];
    }

    std::vector<Point2f> corners;
    for (int i = 0; i < lines.size(); i++)
    {
            for (int j = i+1; j < lines.size(); j++)
            {
                    Point2f pt = computeIntersect(lines[i], lines[j]);
                    if (pt.x >= 0 && pt.y >= 0)
                            corners.push_back(pt);
            }
    }

    std::vector<Point2f> approx;
    approxPolyDP(Mat(corners), approx, arcLength(Mat(corners), true) * 0.02, true);


    // Get mass center
    for (int i = 0; i < corners.size(); i++)
            center += corners[i];
    center *= (1. / corners.size());

    sortCorners(corners, center);

    Mat dst = src.clone();

    // Draw lines
    for (int i = 0; i < lines.size(); i++)
    {
            Vec4i v = lines[i];
            line(dst, Point(v[0], v[1]), Point(v[2], v[3]), CV_RGB(0,255,0));
    }

    // Draw corner points

    circle(dst, corners[3], 3, CV_RGB(255,255,255), 2);
        cout << "Detected " << corners[3] << "\n";

    // Draw mass center
    circle(dst, center, 3, CV_RGB(255,255,0), 2);

    Mat quad = Mat::zeros(300, 220, CV_8UC3);

    std::vector<Point2f> quad_pts;
    quad_pts.push_back(Point2f(0, 0));
    quad_pts.push_back(Point2f(quad.cols, 0));
    quad_pts.push_back(Point2f(quad.cols, quad.rows));
    quad_pts.push_back(Point2f(0, quad.rows));

    Mat transmtx = getPerspectiveTransform(corners, quad_pts);
    warpPerspective(src, quad, transmtx, quad.size());

    imshow("image", bw);
    imshow("images", dst);

    if(waitKey(27) >= 0)  break; }




 return 0;}

檢查這個出來。 希望對您有所幫助,讓我知道。

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