基于比例法和颜色筛选的面积计算

Mat g_srcImage2, g_grayImage2;
vector<Vec4i>g_vHierarchy2;
Mat g_srcImage, g_grayImage;
int main()
{

    VideoCapture capture(0);
    while (1)
    {
        //载入源图像
        system("color 02");
        capture >> g_srcImage;// = imread("D:\\6666.jpg");
        imshow("原图", g_srcImage);
        capture >> g_srcImage2;// = imread("D:\\6666.jpg");
        cvtColor(g_srcImage2, g_grayImage2, COLOR_BGR2HSV);//对图像HSV处理
        inRange(g_grayImage2, Scalar(0, 0, 0), Scalar(180, 255, 46), g_grayImage2);//颜色识别--黑色的标定面积
        imshow("黑色的标定面积", g_grayImage2);

        ////////////////////////////寻找最小矩形边框//////////////////////////////////////////////////////////
        vector<vector<Point>>contours2;
        vector<Vec4i>hierarchy2;
        findContours(g_grayImage2, contours2, hierarchy2, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
        RotatedRect box2;
        double area2 = 0;

        for (int i = 0; i < contours2.size(); i++)
        {
            if (contourArea(contours2[i]) > area2)
            {
                box2 = minAreaRect(contours2[i]);
                area2 = contourArea(contours2[i]);
            }
        }
        Point2f vertex2[4];
        box2.points(vertex2);
        for (int i = 0; i < 4; i++)
        {
            box2.size.width;
            line(g_grayImage2, vertex2[i], vertex2[(i + 1) % 4], Scalar(100, 200, 211), 2, LINE_AA);
        }

        cvtColor(g_srcImage, g_grayImage, COLOR_BGR2HSV);//对图像HSV处理
        inRange(g_grayImage, Scalar(44, 86, 20), Scalar(111, 255, 255), g_grayImage);//电路板识别
                        //寻找最小矩形边框
        vector<vector<Point>>contours;
        vector<Vec4i>hierarchy;
        findContours(g_grayImage, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
        RotatedRect box;
        double area = 0;
        for (int i = 0; i < contours.size(); i++)
        {
            if (contourArea(contours[i]) > area)
            {
                box = minAreaRect(contours[i]);
                area = contourArea(contours[i]);
            }
        }
        Point2f vertex[4];
        box.points(vertex);
        for (int i = 0; i < 4; i++)
        {
            box.size.width;
            line(g_grayImage, vertex[i], vertex[(i + 1) % 4], Scalar(100, 200, 211), 2, LINE_AA);
            system("color 02");
            cout << "宽度" << box.size.width / box2.size.width * 30 << endl << "长度" << box.size.height / box2.size.height * 30 << endl << "面积" << endl << box.size.height * box.size.width / box2.size.height / box2.size.width * 900 << endl;
        }
        waitKey(50);
    }
    return 0;
}