这篇教程OpenCV绘制圆角矩形的方法实例写得很实用，希望能帮到您。
功能函数// 绘制圆角矩形void DrawRotatedRectChamfer(cv::Mat mask,const cv::RotatedRect rotatedrect, float radius,const cv::Scalar &color, int thickness, int lineType){ // 创建画布 cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1); cv::RotatedRect newrotatedrect = rotatedrect; //画宽缩减后的矩形 cv::RotatedRect r1 = newrotatedrect; r1.size.width = r1.size.width - 2 * radius; DrawRotatedRect(canvas, r1, cv::Scalar(255), 5, lineType); //画高缩减后的矩形 cv::RotatedRect r2 = newrotatedrect; r2.size.height = r2.size.height - 2 * radius; DrawRotatedRect(canvas, r2, cv::Scalar(255), 5,lineType); //画四个角的圆 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 } // 绘制旋转矩形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; // 创建一个InputArrayOfArrays 类型的点集 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}测试代码#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;} // 绘制圆角矩形void DrawRotatedRectChamfer(cv::Mat mask,const cv::RotatedRect rotatedrect, float radius,const cv::Scalar &color, int thickness, int lineType){ // 创建画布 cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1); cv::RotatedRect newrotatedrect = rotatedrect; //画宽缩减后的矩形 cv::RotatedRect r1 = newrotatedrect; r1.size.width = r1.size.width - 2 * radius; DrawRotatedRect(canvas, r1, cv::Scalar(255), 5, lineType); //画高缩减后的矩形 cv::RotatedRect r2 = newrotatedrect; r2.size.height = r2.size.height - 2 * radius; DrawRotatedRect(canvas, r2, cv::Scalar(255), 5,lineType); //画四个角的圆 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 } // 绘制旋转矩形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; // 创建一个InputArrayOfArrays 类型的点集 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}测试效果
图1 原图 
图2 绘制圆角矩形 绘制圆角矩形其实是绘制了两个旋转矩形，交叉组合，然后以四交点为圆心绘制圆，就组成了圆角矩形，如图3所示。 
图3 绘制逻辑
同理，这个最好不要绘制到图像外面，否则它在分析外围线的时候会出错，可以多加些判断来修正，我就不写了，交给兄弟们研究一下~ 总结到此这篇关于OpenCV绘制圆角矩形的文章就介绍到这了,更多相关OpenCV绘制圆角矩形内容请搜索51zixue.net以前的文章或继续浏览下面的相关文章希望大家以后多多支持51zixue.net！
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