OpenCV-绘制奥运五环(带套接效果)

简介: OpenCV-绘制奥运五环(带套接效果)

绘制逻辑

      奥运五环由5个同心圆套接组成,有蓝、黄、黑、绿、红5种颜色。环从左到右互相套接,上面是蓝、黑、红环,下面是是黄、绿环。整个造形为一个底部小的规则梯形。大多数人绘制一般只将五个同心圆按顺序排布,但是真正的五环是套接而成,所以本文绘制了带套接效果的奥运五环。


      首先输入绘制的区域信息和五环的环宽,限制下区域宽高和环宽尺寸,避免程序崩溃;其次,正常绘制五个不同颜色的同心圆,以及各自的掩膜图;将交叉的两个环取交集建立交集掩膜图,共有4个交集,分别是蓝色和黄色、黄色和黑色、黑色和绿色、绿色和红色;按照交集区域颜色的优先级,清除交集掩膜图中的非操作区域,对操作区域进行颜色重绘,完毕。


      话不多说,下方为具体实现函数和测试代码。


功能函数代码

// 绘制奥运五环
cv::Mat DrawOlympicRings(cv::Mat src,cv::Rect rect,int w)
{
  if (rect.width < 400)
    rect.width = 400;
  if (rect.height < 400)
    rect.height = 400;
  // 设置五环半径
  int r = min(rect.width, rect.height) / 7;
  if (w > r / 5)
    w = r / 5;
  cv::Mat result = src.clone();
  int row = result.rows;
  int col = result.cols;
  // 蓝色为1,黑色为2,红色为3,黄色为4,绿色为5
  cv::Point point2 = cv::Point(int(rect.x + rect.width / 2), int(rect.y + rect.height / 2 - 0.55*r));
  cv::Point point4 = cv::Point(int(rect.x + rect.width / 2 - 1.1*r), int(rect.y + rect.height / 2 + 0.55*r));
  cv::Point point5 = cv::Point(int(rect.x + rect.width / 2 + 1.1*r), int(rect.y + rect.height / 2 + 0.55*r));
  cv::Point point1 = cv::Point(int(rect.x + rect.width / 2 - 2.2*r), int(rect.y + rect.height / 2 - 0.55*r));
  cv::Point point3 = cv::Point(int(rect.x + rect.width / 2 + 2.2*r), int(rect.y + rect.height / 2 - 0.55*r));
  // 初步绘制同心圆
  DrawConcentricCircle(result, point1, r - w, r, cv::Scalar(255, 0, 0), -1, 16);
  DrawConcentricCircle(result, point2, r - w, r, cv::Scalar(0, 0, 0), -1, 16);
  DrawConcentricCircle(result, point3, r - w, r, cv::Scalar(0, 0, 255), -1, 16);
  DrawConcentricCircle(result, point4, r - w, r, cv::Scalar(0, 255, 255), -1, 16);
  DrawConcentricCircle(result, point5, r - w, r, cv::Scalar(0, 255, 0), -1, 16);
  // 绘制五环掩膜位置
  cv::Mat temp = result.clone();
  cv::Mat mask1 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask1, point1, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask2 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask2, point2, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask3 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask3, point3, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask4 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask4, point4, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask5 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask5, point5, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  // 五环交集
  cv::Mat blury  = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat blacky = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat blackg = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat greenr = cv::Mat::zeros(result.size(), CV_8UC1);
  for (int i = rect.y; i < (rect.y+rect.height); ++i)
  {
    for (int j = rect.x; j < (rect.x+rect.width); ++j)
    {
      if (mask1.at<Vec3b>(i, j)[0] == 255 && mask4.at<Vec3b>(i, j)[0] == 255)
        blury .at<uchar>(i, j) = 255;
      if (mask2.at<Vec3b>(i, j)[0] == 255 && mask4.at<Vec3b>(i, j)[0] == 255)
        blacky.at<uchar>(i, j) = 255;
      if (mask2.at<Vec3b>(i, j)[0] == 255 && mask5.at<Vec3b>(i, j)[0] == 255)
        blackg.at<uchar>(i, j) = 255;
      if (mask3.at<Vec3b>(i, j)[0] == 255 && mask5.at<Vec3b>(i, j)[0] == 255)
        greenr.at<uchar>(i, j) = 255;
    }
  }
  // 目前黄环和绿环压在蓝黑红三环上面
  // 按照五环交叠的规律,消除对应的重叠区,使上面的三环在对应位置反压下面两环
  clearArea(blury , 0);
  clearArea(blacky, 1);
  clearArea(blackg, 0);
  clearArea(greenr, 1);
  for (int i = rect.y; i < (rect.y + rect.height); ++i)
  {
    for (int j = rect.x; j < (rect.x + rect.width); ++j)
    {
      uchar *m1 = blury .ptr<uchar>(i);
      uchar *m2 = blacky.ptr<uchar>(i);
      uchar *m3 = blackg.ptr<uchar>(i);
      uchar *m4 = greenr.ptr<uchar>(i);
      if (m1[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 255;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 0;
      }
      if (m2[j] == 255|| m3[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 0;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 0;
      }
      if (m4[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 0;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 255;
      }
    }
  }
  return result;
}
// 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]);
        }
      }
    }
  }
}
// 清除第id个连通区
void clearArea(cv::Mat& mask, int id)
{
  std::vector<std::vector<cv::Point> > contours;  // 创建轮廓容器
  std::vector<cv::Vec4i>  hierarchy;
  cv::findContours(mask, contours, hierarchy, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_NONE, cv::Point());
  if (!contours.empty() && !hierarchy.empty())
  {
    if (id<contours.size())
    {
      cv::Rect rect = cv::boundingRect(cv::Mat(contours[id]));
      for (int i = rect.y; i < rect.y + rect.height; i++)
      {
        uchar *output_data = mask.ptr<uchar>(i);
        for (int j = rect.x; j < rect.x + rect.width; j++)
        {
          // 将连通区的值置0
          if (output_data[j] == 255)
          {
            output_data[j] = 0;
          }
        }
      }
    }
  }
}


C++测试代码

#include <iostream>
#include <opencv2/opencv.hpp>
#include <time.h>
using namespace std;
using namespace cv;
cv::Mat DrawOlympicRings(cv::Mat src, cv::Rect rect, int w);
void DrawConcentricCircle(cv::Mat mask, const cv::Point2i &center, int radius1, int radius2, const cv::Scalar &color, int thickness, int linetype);
void clearArea(cv::Mat& mask, int id);
int main()
{
  cv::Mat src = imread("test.jpg");
  cv::Mat result = src.clone();
  cv::Rect rect = cv::Rect(10, 10, 800, 800);
  int width = 20;
  clock_t start, end;
  start = clock();
  result = DrawOlympicRings(result,rect,width);
  end = clock();
  double diff = end - start;
  cout << "time:" << diff / CLOCKS_PER_SEC << endl;
  imshow("original", src);
  imshow("result", result);
  waitKey(0);
  system("pause");
  return 0;
}
// 绘制奥运五环
cv::Mat DrawOlympicRings(cv::Mat src,cv::Rect rect,int w)
{
  if (rect.width < 400)
    rect.width = 400;
  if (rect.height < 400)
    rect.height = 400;
  // 设置五环半径
  int r = min(rect.width, rect.height) / 7;
  if (w > r / 5)
    w = r / 5;
  cv::Mat result = src.clone();
  int row = result.rows;
  int col = result.cols;
  // 蓝色为1,黑色为2,红色为3,黄色为4,绿色为5
  cv::Point point2 = cv::Point(int(rect.x + rect.width / 2), int(rect.y + rect.height / 2 - 0.55*r));
  cv::Point point4 = cv::Point(int(rect.x + rect.width / 2 - 1.1*r), int(rect.y + rect.height / 2 + 0.55*r));
  cv::Point point5 = cv::Point(int(rect.x + rect.width / 2 + 1.1*r), int(rect.y + rect.height / 2 + 0.55*r));
  cv::Point point1 = cv::Point(int(rect.x + rect.width / 2 - 2.2*r), int(rect.y + rect.height / 2 - 0.55*r));
  cv::Point point3 = cv::Point(int(rect.x + rect.width / 2 + 2.2*r), int(rect.y + rect.height / 2 - 0.55*r));
  // 初步绘制同心圆
  DrawConcentricCircle(result, point1, r - w, r, cv::Scalar(255, 0, 0), -1, 16);
  DrawConcentricCircle(result, point2, r - w, r, cv::Scalar(0, 0, 0), -1, 16);
  DrawConcentricCircle(result, point3, r - w, r, cv::Scalar(0, 0, 255), -1, 16);
  DrawConcentricCircle(result, point4, r - w, r, cv::Scalar(0, 255, 255), -1, 16);
  DrawConcentricCircle(result, point5, r - w, r, cv::Scalar(0, 255, 0), -1, 16);
  // 绘制五环掩膜位置
  cv::Mat temp = result.clone();
  cv::Mat mask1 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask1, point1, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask2 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask2, point2, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask3 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask3, point3, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask4 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask4, point4, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  cv::Mat mask5 = cv::Mat::zeros(result.size(), CV_8UC3);
  DrawConcentricCircle(mask5, point5, r - w, r, cv::Scalar(255, 255, 255), -1, 16);
  // 五环交集
  cv::Mat blury  = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat blacky = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat blackg = cv::Mat::zeros(result.size(), CV_8UC1);
  cv::Mat greenr = cv::Mat::zeros(result.size(), CV_8UC1);
  for (int i = rect.y; i < (rect.y+rect.height); ++i)
  {
    for (int j = rect.x; j < (rect.x+rect.width); ++j)
    {
      if (mask1.at<Vec3b>(i, j)[0] == 255 && mask4.at<Vec3b>(i, j)[0] == 255)
        blury .at<uchar>(i, j) = 255;
      if (mask2.at<Vec3b>(i, j)[0] == 255 && mask4.at<Vec3b>(i, j)[0] == 255)
        blacky.at<uchar>(i, j) = 255;
      if (mask2.at<Vec3b>(i, j)[0] == 255 && mask5.at<Vec3b>(i, j)[0] == 255)
        blackg.at<uchar>(i, j) = 255;
      if (mask3.at<Vec3b>(i, j)[0] == 255 && mask5.at<Vec3b>(i, j)[0] == 255)
        greenr.at<uchar>(i, j) = 255;
    }
  }
  // 目前黄环和绿环压在蓝黑红三环上面
  // 按照五环交叠的规律,消除对应的重叠区,使上面的三环在对应位置反压下面两环
  clearArea(blury , 0);
  clearArea(blacky, 1);
  clearArea(blackg, 0);
  clearArea(greenr, 1);
  for (int i = rect.y; i < (rect.y + rect.height); ++i)
  {
    for (int j = rect.x; j < (rect.x + rect.width); ++j)
    {
      uchar *m1 = blury .ptr<uchar>(i);
      uchar *m2 = blacky.ptr<uchar>(i);
      uchar *m3 = blackg.ptr<uchar>(i);
      uchar *m4 = greenr.ptr<uchar>(i);
      if (m1[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 255;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 0;
      }
      if (m2[j] == 255|| m3[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 0;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 0;
      }
      if (m4[j] == 255)
      {
        result.at<Vec3b>(i, j)[0] = 0;
        result.at<Vec3b>(i, j)[1] = 0;
        result.at<Vec3b>(i, j)[2] = 255;
      }
    }
  }
  return result;
}
// 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]);
        }
      }
    }
  }
}
// 清除第id个连通区
void clearArea(cv::Mat& mask, int id)
{
  std::vector<std::vector<cv::Point> > contours;  // 创建轮廓容器
  std::vector<cv::Vec4i>  hierarchy;
  cv::findContours(mask, contours, hierarchy, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_NONE, cv::Point());
  if (!contours.empty() && !hierarchy.empty())
  {
    if (id<contours.size())
    {
      cv::Rect rect = cv::boundingRect(cv::Mat(contours[id]));
      for (int i = rect.y; i < rect.y + rect.height; i++)
      {
        uchar *output_data = mask.ptr<uchar>(i);
        for (int j = rect.x; j < rect.x + rect.width; j++)
        {
          // 将连通区的值置0
          if (output_data[j] == 255)
          {
            output_data[j] = 0;
          }
        }
      }
    }
  }
}

测试效果

图1 原图(北京奥运会)

图2 绘制奥运五环

图3 奥运五环

      奥运五环完成啦,和图3是不是很接近,颜色可能有些许差异,只需要改变对应的RGB颜色即可。奥运五环的环上还有白边,可以通过重写同心圆函数DrawConcentricCircle来实现,我就不做啦,感兴趣的兄弟可以自行研究~


      如果函数有什么可以改进完善的地方,非常欢迎大家指出,一同进步何乐而不为呢~


      如果文章帮助到你了,可以点个赞让我知道,我会很快乐~加油!

相关文章
|
11月前
|
开发者
用D3制作一个旋转的大风车SVG庆祝国际儿童节
写于2023年的六一国际儿童节,用D3做一个大风车庆祝一下这个快乐的节日,借此机会介绍一下SVG滤镜的使用,代码也是非常简短的
83 0
用D3制作一个旋转的大风车SVG庆祝国际儿童节
|
1月前
|
计算机视觉 索引 Python
分析”圣诞帽“代码,入门OpenCV
分析”圣诞帽“代码,入门OpenCV
分析”圣诞帽“代码,入门OpenCV
|
10月前
用turtle画“冰墩墩”与“雪容融”同框
用turtle画“冰墩墩”与“雪容融”同框
|
12月前
|
前端开发 JavaScript
径向聚焦,你就是全场最靓的仔
通过mask-image属性我们得到了一个径向聚焦的效果,通过css变量让这个聚焦效果可以随着鼠标的移动而移动,接下来就一起来看看这个效果是如何实现的吧。
41 0
|
12月前
|
数据挖掘
pheatmap|暴雨暂歇,“热图”来袭!!!
pheatmap|暴雨暂歇,“热图”来袭!!!
119 0
|
Python
使用python绘制奥运五环
使用python绘制奥运五环
179 0
使用python绘制奥运五环
|
Python
Python绘制冬奥吉祥物“冰墩墩”
大家好,我是志斌~ 这两天,随着北京冬奥会的开幕,吉祥物“冰墩墩”可是火出了圈,多少人排长队都买不到。据说甚至有人把价格炒到了几千元。 就连昨天的“虎虎生威”文章下面,都有同学求冰墩墩图片
198 0
Python绘制冬奥吉祥物“冰墩墩”
彩铅,卡通小女孩儿
画了个简单的卡通小女孩儿,练练手 图片发自简书App
847 0

热门文章

最新文章