2021-08-19opencv-基于轮廓绘制矩形_opencv 将轮廓合成矩形-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_47434572/article/details/119811542

这篇博客详细介绍了如何在OpenCV中通过处理轮廓来实现轮廓周围绘制矩形的功能，帮助读者掌握这一计算机视觉技术。

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轮廓周围绘制矩形

在这里插入图片描述

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

using namespace cv;
using namespace std;

int threshold_value = 50;
int threshold_max = 255;
Mat src, dst;
const char* output = "output_image";
void contours_demo(int,void*);
RNG rng;

int main() {
	src = imread("D:/b.jpeg");
	if (src.empty()) {
		printf("could not load image");
		return -1;
	}
	namedWindow(output, WINDOW_AUTOSIZE);
	imshow("input", src);
	cvtColor(src,src,COLOR_BGR2GRAY);

	const char* threshold_bar = "threshold_bar";
	createTrackbar(threshold_bar, output, &threshold_value, threshold_max, contours_demo);
	contours_demo(0,0);

	waitKey(0);
	return 0;
}

void contours_demo(int , void*) {
	Mat binary_output;
	vector<vector<Point >> contours;
	vector<Vec4i> hierary;
	 
	threshold(src,binary_output,threshold_value,threshold_max,THRESH_BINARY);
	//imshow(output, binary_output);
	findContours(binary_output,contours,hierary,RETR_TREE,CHAIN_APPROX_SIMPLE,Point(-1,-1));


	vector<vector<Point>>contours_ploy(contours.size());
	vector<Rect>ploy_rect(contours.size());
	vector<Point2f> ccs(contours.size());
	vector<float> radius(contours.size());

	for (size_t i = 0; i < contours.size(); i++) {
		approxPolyDP(Mat(contours[i]), contours_ploy[i], 3, true);
		ploy_rect[i] = boundingRect(contours_ploy[i]);
		minEnclosingCircle(contours_ploy[i], ccs[i], radius[i]);
	}

	//画
	//src.copyTo(dst);
	dst = Mat::zeros(src.size(), CV_8UC4);
	for (size_t i = 0; i < contours.size(); i++) {
		Scalar color = Scalar(rng.uniform(0,255), rng.uniform(0, 255), rng.uniform(0, 255));
		rectangle(dst,ploy_rect[i],color,2,8);
		circle(dst, ccs[i], radius[i], color, 2, 8);
	}

	imshow(output,dst);

	return;
}