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.
Diagram of the rolling ball filter. The filter is applied to the internal aspect of all lung contour points and searches for a contour protrusion composed of non-lung pixels. When a protrusion is found, the filter creates a new contour segment (inset) and eliminates the protrusion.
