Darlis, I know MATLAB has introduced updates to its built-in function convhull across the different versions since MATLAB Version: 7.01. But thanks for letting me know that and for your suggestion, I will examine it further and see if it is worth adding the "simplify" parameter as an option. However, you are free to modify the code.
However, removing vertices that do not contribute to the area will lead to an improper segmentation result. Alternatively, it can be added as a new parameter to the method.
Thank you so much for your great works.
Yes, it run well, and the the code is wery helpfull.
I've found that, the convhull function yield a different result in version 2008a and 2011b. the convhull(x,y) in version 2008a is similar with convhull(x,y,'simplify',true) in version 2011b.
That's why, the 2008 version run faster than 2011a(without parameter simplify).
From the doc (http://www.mathworks.com/help/techdoc/rn/bsk8h3i-1.html#bsljqrp-1)
The simplify option for convhull provides the option of removing vertices that do not contribute to the area or volume of the convex hull.