opencv学习-绘制形状

Posted 2021-06-30 殇堼

point：点的坐标
scalar：颜色向量
绘制线、矩形、圆、椭圆

Scalar表示四个元素的向量

Scalar(a, b, c);// a = blue, b = green, c = red表示RGB三个通道
Scalar color = Scalar(0, 0, 255);//颜色设置为红色

1、绘制直线API- line

         void line(
                InputOutputArray img, //输入图像
                Point pt1, //端点1
                Point pt2, //端点2
                const Scalar& color,//颜色设置
                int thickness = 1, //粗细程度
                int lineType = LINE_8, //直线类型，一共三种：LINE_4，LINE_8，LINE_AA.其中LINE_AA是无锯齿直线。
                int shift = 0//点坐标中的小数位数，一般用默认值0。
            );

1.1端点表示方法

Point表示2D平面上一个点x,y
Point p;
1 p.x = 10; p.y = 8;
或是 2 p = Pont(10,8);

1.2实例代码

#include<opencv2/opencv.hpp>
#include<iostream>
using namespace std;
using namespace cv;
Mat src1 = imread("D:/images/hand.jpg");

void addLine() {
	Point p1, p2;
	p1 = Point(src1.cols / 2, src1.rows / 2);
	p2.x = 10;
	p2.y = 10;
	Scalar color = Scalar(0, 0, 255);
	line(src1, p1, p2, color, 1, LINE_4);
	
}
int main() {
	if (src1.empty()) {
		printf("could not load image...\\n");
		return -1;
	}
	imshow("【input picture】", src1);
	addLine();
	imshow("【addLine】", src1);
	waitKey(0);
}

2、绘制矩形-rectangle

2.1实例代码

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace std;
using namespace cv;
Mat src1 = imread("D:/images/hand.jpg");

void addRectangle()//矩形设置
{
	Rect rect = Rect(20, 10, 150, 200);//左上角坐标（20，10）以及宽（150）、高（200）
	Scalar color = Scalar(0, 0, 255);
	rectangle(src1, rect, color, 1, 4);
}

int main(){
		if (src1.empty()) {
		printf("could not load image...\\n");
		return -1;
	}
	imshow("【input picture】", src1);
	addRectangle();//调用矩形
	imshow("【addRectangle】", src1);//显示调用矩阵后的图像
	waitKey(0);
	destroyAllWindows;
}

3、绘制椭圆-Ellipse

3.1实例代码

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace std;
using namespace cv;
Mat src1 = imread("D:/images/hand.jpg");

void addEllipse()
{
	Point p1 = Point(src1.cols / 2, src1.rows / 2);
	Size s1 = Size(src1.cols / 4, src1.rows / 4);
	Scalar color = Scalar(242, 123, 215);
	ellipse(src1, p1, s1, 40, 0, 360, color, 1, LINE_AA);
}

int main(){
		if (!src1.data) {
		printf("could not load image...\\n");
		return -1;
	}
	imshow("【input picture】", src1);
	addEllipse();
	imshow("【addEllipse】", src1);
	waitKey(0);
}

4.绘制圆

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace std;
using namespace cv;
Mat src1 = imread("D:/images/hand.jpg");

void addCircle(){
	Point center = Point(src1.cols / 2, src1.rows / 2);
	Scalar color = Scalar(0, 255, 255);
	circle(src1, center, 50, color, 1, 4);
}

int main(){
		if (src1.empty()) {
		printf("could not load image...\\n");
		return -1;
	}
	imshow("【input picture】", src1);
	addCircle();
	imshow("【addCircle】", src1);
	waitKey(0);
}