I am new to OpenCV and to this forum. This is a great tutorial with simplicity that makes it quick and easy to understand. However, the code would not compile on my Visual Studio 2010 without the following modifications:

The following line was modified:
<pre>
minEnclosingCircle( contours_poly[i], center[i], radius[i] );
</pre>

I had to cast the contours_poly to a Mat type as in the following:
<pre>
minEnclosingCircle( (Mat)contours_poly[i], center[i], radius[i] );
</pre>

After this modification it worked great.