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
图1 原图
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。
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。
图4 外围线
然后,你就会得到一个奇葩图形,如图5所示。
图5 示意图
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