Draw rectangle in OpenCV

Question

I want to draw a rectangle in OpenCV by using this function:

rectangle(Mat& img, Rect rec, const Scalar& color, int thickness=1, int lineType=8, int shif         


        

Answer 1

Here's a simple example of drawing a pre-defined rectangle on an image

using namespace cv;

int main(){
Mat img=imread("myImage.jpg");

Rect r=Rect(10,20,40,60);
//create a Rect with top-left vertex at (10,20), of width 40 and height 60 pixels.

rectangle(img,r,Scalar(255,0,0),1,8,0);
//draw the rect defined by r with line thickness 1 and Blue color

imwrite("myImageWithRect.jpg",img);


return 0;
}