Shepp–Logan phantom

The Shepp–Logan phantom is a standard test image created by Larry Shepp and Benjamin F. Logan for their 1974 paper "The Fourier Reconstruction of a Head Section".

[1] It serves as the model of a human head in the development and testing of image reconstruction algorithms.

[2][3][4] The function describing the phantom is defined[1] as the sum of 10 ellipses inside a 2×2 square:

Image of the Shepp–Logan Phantom