脚本之家,脚本语言编程技术及教程分享平台!
分类导航

Python|VBS|Ruby|Lua|perl|VBA|Golang|PowerShell|Erlang|autoit|Dos|bat|

服务器之家 - 脚本之家 - Python - OpenCV绘制圆端矩形的示例代码

OpenCV绘制圆端矩形的示例代码

2021-12-26 14:12翟天保Steven Python

本文主要介绍了OpenCV绘制圆端矩形的示例代码,文中通过示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们可以参考一下

本文主要介绍了OpenCV绘制圆端矩形的示例代码,分享给大家,具体如下:

 

功能函数

// 绘制圆端矩形(药丸状,pill)
void DrawPill(cv::Mat mask, const cv::RotatedRect &rotatedrect, const cv::Scalar &color, int thickness, int lineType)
{
	cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);
	// 确定短边,短边绘制圆形
	cv::RotatedRect rect = rotatedrect;
	float r = rect.size.height / 2.0f;
	if (rect.size.width > rect.size.height) {
		rect.size.width -= rect.size.height;
	}
	else {
		rect.size.height -= rect.size.width;
		r = rect.size.width / 2.0f;
	}
	cv::Point2f ps[4];
	rect.points(ps);
 
	// 绘制边缘
	std::vector<std::vector<cv::Point>> tmpContours;
	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(canvas, tmpContours, 0, cv::Scalar(255),5, lineType);  // 填充mask
 
	// 计算常长短轴
	float a = rotatedrect.size.width;
	float b = rotatedrect.size.height;
 
	int point01_x = (int)((ps[0].x + ps[1].x) / 2.0f);
	int point01_y = (int)((ps[0].y + ps[1].y) / 2.0f);
	int point03_x = (int)((ps[0].x + ps[3].x) / 2.0f);
	int point03_y = (int)((ps[0].y + ps[3].y) / 2.0f);
	int point12_x = (int)((ps[1].x + ps[2].x) / 2.0f);
	int point12_y = (int)((ps[1].y + ps[2].y) / 2.0f);
	int point23_x = (int)((ps[2].x + ps[3].x) / 2.0f);
	int point23_y = (int)((ps[2].y + ps[3].y) / 2.0f);
 
	cv::Point c0 = a < b ? cv::Point(point12_x, point12_y) : cv::Point(point23_x, point23_y);
	cv::Point c1 = a < b ? cv::Point(point03_x, point03_y) : cv::Point(point01_x, point01_y);
 
	// 长轴两端以填充的方式画圆,直径等于短轴
	cv::circle(canvas, c0, (int)r, cv::Scalar(255), 5, lineType);
	cv::circle(canvas, c1, (int)r, cv::Scalar(255), 5, lineType);
 
	// 绘制外围轮廓,如果不这样操作,会得到一个矩形加两个圆形,丑。。。
	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
}

 

测试代码

#include <iostream>
#include <opencv2/opencv.hpp>
 
using namespace std;
using namespace cv;
 
void DrawPill(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(1000, 800), 50);
	DrawPill(result, rorect, cv::Scalar(0, 255, 255),8,16);
	imshow("original", src);
	imshow("result", result);
	waitKey(0);
	return 0;
}
 
// 绘制圆端矩形(药丸状,pill)
void DrawPill(cv::Mat mask, const cv::RotatedRect &rotatedrect, const cv::Scalar &color, int thickness, int lineType)
{
	cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);
	// 确定短边,短边绘制圆形
	cv::RotatedRect rect = rotatedrect;
	float r = rect.size.height / 2.0f;
	if (rect.size.width > rect.size.height) {
		rect.size.width -= rect.size.height;
	}
	else {
		rect.size.height -= rect.size.width;
		r = rect.size.width / 2.0f;
	}
	cv::Point2f ps[4];
	rect.points(ps);
 
	// 绘制边缘
	std::vector<std::vector<cv::Point>> tmpContours;
	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(canvas, tmpContours, 0, cv::Scalar(255),5, lineType);  // 填充mask
 
	// 计算常长短轴
	float a = rotatedrect.size.width;
	float b = rotatedrect.size.height;
 
	int point01_x = (int)((ps[0].x + ps[1].x) / 2.0f);
	int point01_y = (int)((ps[0].y + ps[1].y) / 2.0f);
	int point03_x = (int)((ps[0].x + ps[3].x) / 2.0f);
	int point03_y = (int)((ps[0].y + ps[3].y) / 2.0f);
	int point12_x = (int)((ps[1].x + ps[2].x) / 2.0f);
	int point12_y = (int)((ps[1].y + ps[2].y) / 2.0f);
	int point23_x = (int)((ps[2].x + ps[3].x) / 2.0f);
	int point23_y = (int)((ps[2].y + ps[3].y) / 2.0f);
 
	cv::Point c0 = a < b ? cv::Point(point12_x, point12_y) : cv::Point(point23_x, point23_y);
	cv::Point c1 = a < b ? cv::Point(point03_x, point03_y) : cv::Point(point01_x, point01_y);
 
	// 长轴两端以填充的方式画圆,直径等于短轴
	cv::circle(canvas, c0, (int)r, cv::Scalar(255), 5, lineType);
	cv::circle(canvas, c1, (int)r, cv::Scalar(255), 5, lineType);
 
	// 绘制外围轮廓,如果不这样操作,会得到一个矩形加两个圆形,丑。。。
	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
}

 

测试效果

OpenCV绘制圆端矩形的示例代码

图1 原图

OpenCV绘制圆端矩形的示例代码

图2 绘制圆端矩形

绘制圆端矩形其实就是绘制了一个旋转矩形,然后分析哪个轴更长,就在哪个轴上的两端画圆,再取外围轮廓,大功告成,通俗来讲就画了一个矩形两个圆,如图3所示。

OpenCV绘制圆端矩形的示例代码

图3 绘制逻辑

不过注意,这个图形最好不要超过图像边界,因为超过后再分析外围轮廓,它认为的外围就到了内部,如图4所示。

OpenCV绘制圆端矩形的示例代码

图4 外围线

然后,你就会得到一个奇葩图形,如图5所示。

OpenCV绘制圆端矩形的示例代码

图5 示意图

到此这篇关于OpenCV绘制圆端矩形的示例代码的文章就介绍到这了,更多相关OpenCV 圆端矩形内容请搜索服务器之家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服务器之家!

原文链接:https://blog.csdn.net/zhaitianbao/article/details/119945580

延伸 · 阅读

精彩推荐