// Original Shepp-Logan two-dimensional phantom // [Shepp and Logan, The Fourier Reconstruction of a Head Section, 1974] [Ellipsoid] A=0.69 B=0 C=0.92 x=0 y=0 z=0 beta=0 gray=2.0 // a [Ellipsoid] A=0.6624 B=0 C=0.874 x=0 y=0 z=-0.0184 beta=0 gray=-0.98 // b [Ellipsoid] A=0.11 B=0 C=0.31 x=0.22 y=0 z=0 beta=-18 gray=-0.02 // c [Ellipsoid] A=0.16 B=0 C=0.41 x=-0.22 y=0 z=0 beta=18 gray=-0.02 // d [Ellipsoid] A=0.21 B=0 C=0.25 x=0 y=0 z=0.35 beta=0 gray=0.01 // e [Ellipsoid] A=0.046 B=0 C=0.046 x=0 y=0 z=0.1 beta=0 gray=0.01 // f [Ellipsoid] A=0.046 B=0 C=0.046 x=0 y=0 z=-0.1 beta=0 gray=0.01 // g [Ellipsoid] A=0.046 B=0 C=0.023 x=-0.08 y=0 z=-0.605 beta=0 gray=0.01 // h [Ellipsoid] A=0.023 B=0 C=0.023 x=0 y=0 z=-0.605 beta=0 gray=0.01 // i [Ellipsoid] A=0.023 B=0 C=0.046 x=0.06 y=0 z=-0.605 beta=0 gray=0.01 // j