Opencv 的各个vector容器探究

Posted 2021-12-06 流楚丶格念

各个vector

放了一个vector容器，子容器里放点

vector<vector<Point>>

放了4维int向量

vector<Vec4i>

像素width * height from 位置(x*y)

vector<Rect>

矩形偏移角度、中心、大小

vector<RotatedRect>

轮廓周围绘制矩形框

刚开始学OpenCV没多久遇到这些个东西不知道是什么，搞得很不舒服。

通过给轮廓绘制矩形框弄明白了这些东西。

代码如下：

#include <iostream>
#include <math.h>
#include <opencv2/opencv.hpp>
#include<opencv2/highgui.hpp>
#include <opencv2/highgui/highgui_c.h>  

using namespace std;
using namespace cv;

int main() {
	Mat src, gray_src, drawImg, bin_output;

	src = imread("./shape.png");
	namedWindow("input", CV_WINDOW_AUTOSIZE);
	namedWindow("output", CV_WINDOW_AUTOSIZE);
	imshow("input", src);

	cvtColor(src, gray_src, CV_BGR2GRAY);		// 灰度图
	blur(gray_src, gray_src, Size(10, 10), Point(-1, -1), BORDER_DEFAULT);

	//这些个类型
	vector<vector<Point>> contours;		// 存轮廓
	vector<Vec4i> hierarchy;			// 轮廓关系向量

	threshold(gray_src, bin_output, 144, 255, 0);													// 二值化
	findContours(bin_output, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(0, 0));		// 找轮廓

	//这些个类型
	vector<vector<Point>> contours_poly(contours.size());
	vector<Rect> poly_rects(contours.size());
	vector<RotatedRect> minRect(contours.size());

	//取点
	for (size_t i = 0; i < contours.size(); i++)
	{
		approxPolyDP(Mat(contours[i]), contours_poly[i], 3, true); //减少轮廓点数

		poly_rects[i] = boundingRect(contours_poly[i]);//获取绘制矩形数据

		if (contours_poly[i].size() > 5) {
			minRect[i] = minAreaRect(contours_poly[i]);//获取绘制旋转矩形数据
		}
	}

	// 开始绘制
	src.copyTo(drawImg);
	Point2f pst[4];					// 储存单个旋转矩形的四个点
	cout << "----------Point2f pst[4]：输出每个旋转矩形的四个点坐标------------" << endl;
	for (size_t i = 0; i < contours.size(); i++)
	{
		rectangle(drawImg, poly_rects[i], Scalar(255, 0, 0), 2, 8);//绘制矩形框

		minRect[i].points(pst);//用线段画矩形，将RotatedRect类型转化为四个点	

		for (size_t u = 0; u < 4; u++)
		{
			line(drawImg, pst[u], pst[(u + 1) % 4], Scalar(0, 255, 0), 2, 8);
			cout << pst[u];			// 显示pst的数据
		}
		cout << endl;
		Rect brect = minRect[i].boundingRect(); //返回包含旋转矩形的最小矩形  
		rectangle(drawImg, brect, Scalar(0, 0, 255));
	}
	cout << endl;
	imshow("output", drawImg);

	cout << "----------vector<vector<Point>> contours_poly：------------" << endl;
	for (size_t i = 0; i < contours_poly.size(); i++)
	{
		cout << "第" << i << "行：";
		for (size_t j = 0; j < contours_poly[i].size(); j++)
		{
			cout << contours_poly[i][j];
		}
		cout << endl;
	}
	cout << endl;

	cout << "----------vector<Vec4i> hierarchy：输出轮廓间关系------------" << endl;
	for (size_t i = 0; i < hierarchy.size(); i++)
	{
		cout << hierarchy[i] << endl;
	}
	cout << endl;

	cout << "----------vector<Rect> poly_rects------------" << endl;
	for (size_t i = 0; i < poly_rects.size(); i++)
	{
		cout << poly_rects[i] << endl;
	}
	cout << endl;

	cout << "---------vector<RotatedRect> minRect------------" << endl;
	for (size_t i = 0; i < minRect.size(); i++)	//显示一下点minRect
	{
		cout << "angle:" << minRect[i].angle << " center:" << minRect[i].center << " size:" << minRect[i].size << endl;
	}
	cout << endl;

	waitKey(0);
	return 0;
}

运行结果为：