How can i draw a circle at a particular centroid?

How can i draw a circle at a particular centroid? I have an image displayed by the function imshow.. I need to draw circle of a particular diameter on the image..

Answer 1

[Image Analyst]

I just answered this for someone.

hold on;
plot(xCenter, yCenter, 'bo', 'MarkerSize', 30);

Adjust MarkerSize to get different diameter.

If you have row,column instead of x,y, do this:

hold on;
plot(centerColumn, centerRow, 'bo', 'MarkerSize', 30);

[MoonPie1]

Is there any alternative instead of Markersize?