determining the edges of the money image with red color

how can I draw the edges of the money image below in color? I'm trying the following code, but it doesn't work

A = imread('eight.tif');

figure,imshow(A)

d=imdistline;

[centers,radi] = imfindcircles(A,[20 25]);

figure,imshow(A);

viscircles(centers, radi,'Color','r');

Answer 1

[Simon Chan]

It is better to ask imfindcircles to find all the dark circles and adjust the range of radius.

In your case, the range is too small and imfindcircles cannot find any circle for you.

Try the following

[centers, radi] = imfindcircles(A,[20 50],'ObjectPolarity','dark')

[betty]

thank you very much I tried and it worked

[Image Analyst]

Then please "Accept this answer" to award Simon his reputation points. 🙂