How can I draw a circle on an image in MATLAB?

 I have an image in MATLAB: 

 

 im = rgb2gray(imread('some_image.jpg');
% normalize the image to be between 0 and 1
im = im/max(max(im));

And I've done some processing that resulted in a number of points that I want to highlight: 

 

points = some_processing(im);

Where points is a matrix the same size as im with ones in the interesting points.

Now I want to draw a circle on the image in all the places where points is 1.

Is there any function in MATLAB that does this? The best I can come up with is: 

 

 [x_p, y_p] = find (points);

[x, y] = meshgrid(1:size(im,1), 1:size(im,2))
r = 5;

circles = zeros(size(im));

for k = 1:length(x_p)
    circles = circles + (floor((x - x_p(k)).^2 + (y - y_p(k)).^2) == r);
end

% normalize circles
circles = circles/max(max(circles));

output = im + circles;

imshow(output)

This seems more than somewhat inelegant. Is there a way to draw circles similar to the line function?  


NOTE:-


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Answers: 

You could use the normal PLOT command with a circular marker point: 

 

 [x_p,y_p] = find(points);
imshow(im);         %# Display your image
hold on;            %# Add subsequent plots to the image
plot(y_p,x_p,'o');  %# NOTE: x_p and y_p are switched (see  
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