【原】OpenCV-绘制同心圆

翟天保的图书馆 2022-01-13

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作者：翟天保Steven
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功能函数

// 绘制同心圆
void DrawConcentricCircle(cv::Mat mask, const cv::Point2i &center, int radius1,int radius2, const cv::Scalar &color, int thickness,int linetype)
{
// 创建画布
cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);

// 计算内径和外径
int inradius = min(radius1, radius2);
int outradius = max(radius1, radius2);

// 分情况讨论
// 当thickness大于0时，绘制的是两个圆型线条组成的同心圆，不需填充
if (thickness > 0)
{
cv::circle(mask, center, outradius, color, thickness, linetype);
cv::circle(mask, center, inradius, color, thickness, linetype);
}
// 当thickness小于0，一般为-1，绘制的是填充同心圆，内圆不能有填充色
else {
cv::circle(canvas, center, outradius, cv::Scalar(255), -1, linetype);
cv::circle(canvas, center, inradius, cv::Scalar(0), -1, linetype);
int row = mask.rows;
int col = mask.cols;
for (int i = 0; i < row; ++i)
{
for (int j = 0; j < col; ++j)
{
uchar *m = canvas.ptr<uchar>(i);
if (m[j] == 255)
{
mask.at<Vec3b>(i, j)[0] = static_cast<uchar>(color[0]);
mask.at<Vec3b>(i, j)[1] = static_cast<uchar>(color[1]);
mask.at<Vec3b>(i, j)[2] = static_cast<uchar>(color[2]);
}

}
}
}
}

测试代码

#include <iostream>
#include <opencv2/opencv.hpp>
#include <stdio.h>
using namespace std;
using namespace cv;

void DrawConcentricCircle(cv::Mat mask, const cv::Point2i &center, int radius1, int radius2, const cv::Scalar &color, int thickness, int linetype);

int main()
{
cv::Mat src = imread("test.jpg");
cv::Mat result = src.clone();
DrawConcentricCircle(result, cv::Point(result.cols / 2, result.rows / 2), 300, 500, cv::Scalar(255, 255, 0),-10, 16);
imshow("original", src);
imshow("result", result);
waitKey(0);
system("pause");
return 0;
}

// 绘制同心圆
void DrawConcentricCircle(cv::Mat mask, const cv::Point2i &center, int radius1,int radius2, const cv::Scalar &color, int thickness,int linetype)
{
// 创建画布
cv::Mat canvas = cv::Mat::zeros(mask.size(), CV_8UC1);

// 计算内径和外径
int inradius = min(radius1, radius2);
int outradius = max(radius1, radius2);

// 分情况讨论
// 当thickness大于0时，绘制的是两个圆型线条组成的同心圆，不需填充
if (thickness > 0)
{
cv::circle(mask, center, outradius, color, thickness, linetype);
cv::circle(mask, center, inradius, color, thickness, linetype);
}
// 当thickness小于0，一般为-1，绘制的是填充同心圆，内圆不能有填充色
else {
cv::circle(canvas, center, outradius, cv::Scalar(255), -1, linetype);
cv::circle(canvas, center, inradius, cv::Scalar(0), -1, linetype);
int row = mask.rows;
int col = mask.cols;
for (int i = 0; i < row; ++i)
{
for (int j = 0; j < col; ++j)
{
uchar *m = canvas.ptr<uchar>(i);
if (m[j] == 255)
{
mask.at<Vec3b>(i, j)[0] = static_cast<uchar>(color[0]);
mask.at<Vec3b>(i, j)[1] = static_cast<uchar>(color[1]);
mask.at<Vec3b>(i, j)[2] = static_cast<uchar>(color[2]);
}

}
}
}
}