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.
Dependence of the mean contrast of the horizontal line pairs in the LPBB phantom on the group location and the source: (a) dependence on the group location for Source 0 (ideal point source); (b) dependence on the group location for Source 3; (c) dependence on the source for Group 1; (d) dependence on the source for Group 5.
