Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
(a) Feature regions extracted corresponding to vertices marked with blue in the minimum curvature color map. (b) Feature region before and after being applied for opening and closing operation; (c) Feature regions of (a) after being processed further.
