使用 OpenCV 在图像上绘制折线

图像处理 • 2022年11月25日上午11:42 • 技术文章

OpenCV 提供了绘制几何形状的功能，例如直线、矩形、圆形等。

该polylines函数可用于绘制折线。它是由一个或多个线段组成的连续线。

import cv2
import numpy as np

img = np.zeros((100, 300, 3), dtype=np.uint8)

points = np.array([[100, 60], [140, 20], [180, 20], [220, 60]])
isClosed = True
color = (0, 255, 0)
thickness = 2
cv2.polylines(img, [points], isClosed, color, thickness)

cv2.imshow('Image', img)
cv2.waitKey(0)
cv2.destroyAllWindows()

#include <opencv2/opencv.hpp>

using namespace cv;

int main()
{
    Mat img = Mat::zeros(100, 300, CV_8UC3);

    std::vector<std::vector<Point>> points = {
        {Point(100, 60), Point(140, 20), Point(180, 20), Point(220, 60)}
    };
    bool isClosed = true;
    Scalar color(0, 255, 0);
    int thickness = 2;
    polylines(img, points, isClosed, color, thickness);

    imshow("Image", img);
    waitKey(0);
    destroyAllWindows();

    return 0;
}

package app;

import org.opencv.core.*;
import org.opencv.highgui.HighGui;
import org.opencv.imgproc.Imgproc;
import java.util.ArrayList;
import java.util.List;

public class Main
{
    static { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }

    public static void main(String[] args)
    {
        Mat img = Mat.zeros(100, 300, CvType.CV_8UC3);

        List<MatOfPoint> points = new ArrayList<>();
        points.add(
            new MatOfPoint(
                new Point(100, 60), new Point(140, 20),
                new Point(180, 20), new Point(220, 60)
            )
        );
        boolean isClosed = true;
        Scalar color = new Scalar(0, 255, 0);
        int thickness = 2;
        Imgproc.polylines(img, points, isClosed, color, thickness);

        HighGui.imshow("Image", img);
        HighGui.waitKey(0);
        HighGui.destroyAllWindows();

        System.exit(0);
    }
}

结果：