java+opencv4.5.0 实现获取图片红色区域，并且用线条连接每个区域

要实现这个功能，你需要使用 Java 的 OpenCV 库。下面是一个简单的步骤：

1. 导入 OpenCV 库

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

2. 加载图片

Mat image = Imgcodecs.imread("path/to/image.jpg");

3. 将图像转换为 HSV 颜色空间

Mat hsvImage = new Mat();
Imgproc.cvtColor(image, hsvImage, Imgproc.COLOR_BGR2HSV);

4. 用 inRange 函数获取红色区域的二值图像

Mat redMask = new Mat();
Scalar lowerRed = new Scalar(0, 100, 100);
Scalar upperRed = new Scalar(10, 255, 255);
Core.inRange(hsvImage, lowerRed, upperRed, redMask);

5. 对二值图像进行形态学操作，去掉噪点

Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5));
Imgproc.morphologyEx(redMask, redMask, Imgproc.MORPH_OPEN, kernel);
Imgproc.morphologyEx(redMask, redMask, Imgproc.MORPH_CLOSE, kernel);

6. 用 findContours 函数获取红色区域的轮廓

List<MatOfPoint> contours = new ArrayList<>();
Mat hierarchy = new Mat();
Imgproc.findContours(redMask, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

7. 用 drawContours 函数将轮廓连接起来

Imgproc.drawContours(image, contours, -1, new Scalar(0, 0, 255), 2);

完整的代码示例：

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.core.MatOfPoint;
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 image = Imgcodecs.imread("path/to/image.jpg");

        Mat hsvImage = new Mat();
        Imgproc.cvtColor(image, hsvImage, Imgproc.COLOR_BGR2HSV);

        Mat redMask = new Mat();
        Scalar lowerRed = new Scalar(0, 100, 100);
        Scalar upperRed = new Scalar(10, 255, 255);
        Core.inRange(hsvImage, lowerRed, upperRed, redMask);

        Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5));
        Imgproc.morphologyEx(redMask, redMask, Imgproc.MORPH_OPEN, kernel);
        Imgproc.morphologyEx(redMask, redMask, Imgproc.MORPH_CLOSE, kernel);

        List<MatOfPoint> contours = new ArrayList<>();
        Mat hierarchy = new Mat();
        Imgproc.findContours(redMask, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

        Imgproc.drawContours(image, contours, -1, new Scalar(0, 0, 255), 2);

        Imgcodecs.imwrite("path/to/output.jpg", image);
    }
}

这样就可以实现获取图片红色区域，并用线条连接每个区域的功能啦！