OpenCV繪制圓角矩形的方法實(shí)例

更新時間：2021年08月31日 10:47:01 作者：翟天保Steven

我們在輪廓截取出來時一般需要是矩形的圖像,所以下面這篇文章主要給大家介紹了關(guān)于OpenCV繪制圓角矩形的相關(guān)資料,文中通過示例代碼介紹的非常詳細(xì),需要的朋友可以參考下

功能函數(shù)

// 繪制圓角矩形
void DrawRotatedRectChamfer(cv::Mat mask,const cv::RotatedRect rotatedrect, float radius,const cv::Scalar &color, int thickness, int lineType)
{
	// 創(chuàng)建畫布
	cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);
 
	cv::RotatedRect newrotatedrect = rotatedrect;
 
	//畫寬縮減后的矩形
	cv::RotatedRect r1 = newrotatedrect;
	r1.size.width = r1.size.width - 2 * radius;
	DrawRotatedRect(canvas, r1, cv::Scalar(255), 5, lineType);
 
	//畫高縮減后的矩形
	cv::RotatedRect r2 = newrotatedrect;
	r2.size.height = r2.size.height - 2 * radius;
	DrawRotatedRect(canvas, r2, cv::Scalar(255), 5,lineType);
 
	//畫四個角的圓
	cv::RotatedRect r3 = r2;
	r3.size.width = r1.size.width;
 
	cv::Point2f ps[4];
	r3.points(ps);
 
	for (int i = 0; i != 4; ++i) {
		cv::circle(canvas, ps[i], (int)radius, cv::Scalar(255), 5);
	}
	std::vector<std::vector<cv::Point>> EXcontours;
	cv::findContours(canvas, EXcontours, cv::RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
	drawContours(mask, EXcontours, 0, color, thickness, lineType);  // 填充mask
 
}
 
// 繪制旋轉(zhuǎn)矩形
void DrawRotatedRect(cv::Mat mask,const cv::RotatedRect rotatedrect,const cv::Scalar &color, int thickness,int lineType)
{
	cv::Point2f ps[4];
	rotatedrect.points(ps);
 
	std::vector<std::vector<cv::Point>> tmpContours;    // 創(chuàng)建一個InputArrayOfArrays 類型的點(diǎn)集
	std::vector<cv::Point> contours;
	for (int i = 0; i != 4; ++i) {
		contours.emplace_back(cv::Point2i(ps[i]));
	}
	tmpContours.insert(tmpContours.end(), contours);
	drawContours(mask, tmpContours, 0, color, thickness, lineType);  // 填充mask
}

測試代碼

#include <iostream>
#include <opencv2/opencv.hpp>
#include <stdio.h>
using namespace std;
using namespace cv;
 
void DrawRotatedRectChamfer(cv::Mat mask, const cv::RotatedRect rotatedrect, float radius, const cv::Scalar &color, int thickness, int lineType);
void DrawRotatedRect(cv::Mat mask, const cv::RotatedRect rotatedrect, const cv::Scalar &color, int thickness, int lineType);
 
int main()
{
	cv::Mat src = imread("test.jpg");
	cv::Mat result = src.clone();
	cv::RotatedRect rorect(cv::Point(src.cols / 2, src.rows / 2), cv::Size(800, 600), 50);
	DrawRotatedRectChamfer(result, rorect, 100, cv::Scalar(0, 0, 255), 5, 16);
	imshow("original", src);
	imshow("result", result);
	waitKey(0);
	return 0;
}
 
// 繪制圓角矩形
void DrawRotatedRectChamfer(cv::Mat mask,const cv::RotatedRect rotatedrect, float radius,const cv::Scalar &color, int thickness, int lineType)
{
	// 創(chuàng)建畫布
	cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);
 
	cv::RotatedRect newrotatedrect = rotatedrect;
 
	//畫寬縮減后的矩形
	cv::RotatedRect r1 = newrotatedrect;
	r1.size.width = r1.size.width - 2 * radius;
	DrawRotatedRect(canvas, r1, cv::Scalar(255), 5, lineType);
 
	//畫高縮減后的矩形
	cv::RotatedRect r2 = newrotatedrect;
	r2.size.height = r2.size.height - 2 * radius;
	DrawRotatedRect(canvas, r2, cv::Scalar(255), 5,lineType);
 
	//畫四個角的圓
	cv::RotatedRect r3 = r2;
	r3.size.width = r1.size.width;
 
	cv::Point2f ps[4];
	r3.points(ps);
 
	for (int i = 0; i != 4; ++i) {
		cv::circle(canvas, ps[i], (int)radius, cv::Scalar(255), 5);
	}
	std::vector<std::vector<cv::Point>> EXcontours;
	cv::findContours(canvas, EXcontours, cv::RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
	drawContours(mask, EXcontours, 0, color, thickness, lineType);  // 填充mask
 
}
 
// 繪制旋轉(zhuǎn)矩形
void DrawRotatedRect(cv::Mat mask,const cv::RotatedRect rotatedrect,const cv::Scalar &color, int thickness,int lineType)
{
	cv::Point2f ps[4];
	rotatedrect.points(ps);
 
	std::vector<std::vector<cv::Point>> tmpContours;    // 創(chuàng)建一個InputArrayOfArrays 類型的點(diǎn)集
	std::vector<cv::Point> contours;
	for (int i = 0; i != 4; ++i) {
		contours.emplace_back(cv::Point2i(ps[i]));
	}
	tmpContours.insert(tmpContours.end(), contours);
	drawContours(mask, tmpContours, 0, color, thickness, lineType);  // 填充mask
}