circle() function

Draws a circle.

C++: void circle(Mat& img, Point center, int radius, const Scalar& color, int thickness=1, int lineType=8, int shift=0)

Parameters:

img – Image where the circle is drawn. center – Center of the circle. radius – Radius of the circle. color – Circle color. thickness – Thickness of the circle outline, if positive. Negative thickness means that a filled circle is to be drawn. lineType – Type of the circle boundary. See the line() description. shift – Number of fractional bits in the coordinates of the center and in the radius value.

The function circle draws a simple or filled circle with a given center and radius.

 circle(img_show,center,3,Scalar(0,0,255),-1);

radius: 3

thickness: -1, filled circle




 

 circle(img_show,center,radius,Scalar(0,0,255),3,8,0);

radius: as detected

thickness: 3

line type: 8 

• 8 (or omitted) - 8-connected line.
• 4 - 4-connected line.

    shift: 0