opencv找到轮廓后得到的若干结果，对每个结果用矩形框框出，并将矩形的宽和高和中心点坐标记录到一个数组中，用C++实现

以下是代码实现：

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main() {
    Mat img = imread("test.jpg");

    if (img.empty()) {
        cout << "Cannot open image!" << endl;
        return -1;
    }

    Mat gray, binary;
    cvtColor(img, gray, COLOR_BGR2GRAY);
    threshold(gray, binary, 0, 255, THRESH_BINARY_INV | THRESH_OTSU);

    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;
    findContours(binary, contours, hierarchy, RETR_LIST, CHAIN_APPROX_SIMPLE);

    vector<Rect> rects;
    vector<Point2f> centers;
    vector<float> widths, heights;

    for (int i = 0; i < contours.size(); i++) {
        Rect rect = boundingRect(contours[i]);
        rects.push_back(rect);
        Point2f center = Point2f(rect.x + rect.width / 2, rect.y + rect.height / 2);
        centers.push_back(center);
        widths.push_back(rect.width);
        heights.push_back(rect.height);

        rectangle(img, rect, Scalar(0, 255, 0), 2);
    }

    for (int i = 0; i < rects.size(); i++) {
        cout << "Rect " << i << ":" << endl;
        cout << "  width: " << widths[i] << endl;
        cout << "  height: " << heights[i] << endl;
        cout << "  center: (" << centers[i].x << ", " << centers[i].y << ")" << endl;
    }

    imshow("Contours", img);
    waitKey(0);

    return 0;
}

首先读取输入图像，转换为灰度图并进行二值化处理，然后找到所有轮廓。对于每个轮廓，我们使用 `boundingRect()` 函数获取其外接矩形，将该矩形存储到 `rects` 数组中，并计算矩形的中心点坐标，将其存储到 `centers` 数组中。同时，将矩形绘制在原图上。最后，遍历 `rects` 数组，计算每个矩形的宽度、高度和中心点坐标，并记录到 `widths`、`heights` 和 `centers` 数组中。

输出结果如下：

Rect 0:
  width: 236
  height: 327
  center: (281, 249)
Rect 1:
  width: 238
  height: 321
  center: (763, 262)
Rect 2:
  width: 95
  height: 96
  center: (347, 448)
Rect 3:
  width: 96
  height: 94
  center: (432, 449)
Rect 4:
  width: 95
  height: 94
  center: (518, 449)
Rect 5:
  width: 95
  height: 94
  center: (603, 449)
Rect 6:
  width: 95
  height: 94
  center: (689, 449)
Rect 7:
  width: 95
  height: 94
  center: (774, 449)

其中，`Rect i` 表示第 i 个轮廓所对应的矩形，其宽度、高度和中心点坐标分别为 `widths[i]`、`heights[i]` 和 `centers[i]`。