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) A comparison of correlation coefficience for different point sources using different geometrical projection matrices together with different resolution kernels with (EM) and without (LS) nonnegativity constraint. (b) The change of CC as a function of voxel size for different geometrical projectors. ‘circle’: Siddon's raytracer, ‘diamond’: Bresenham's raytracer.
