Finding circle in binary image (R, not matlab)

1. How do I search for a circle in a picture?
2. How do I add a circle to an image in Matlab?

How do I search for a circle in a picture?

Edge detection. In order to detect the circles, or any other geometric shape, we first need to detect the edges of the objects present in the image. The edges in an image are the points for which there is a sharp change of color. For instance, the edge of a red ball on a white background is a circle.

How do I add a circle to an image in Matlab?

Insert Circle and Filled Shapes on an Image

I = imread("peppers. png"); Draw a circle on the image with a border line width of 5. RGB = insertShape(I,"circle",[150 280 35],LineWidth=5);