  By encoding the high-dimensional light-field imaging information into a
detectable two-dimensional speckle plane, ghost imaging camera via sparsity
constraints (GISC camera) can directly catch the high-dimensional light-field
imaging information with only one snapshot. This makes it worth to revisit the
spatial resolution limit of this optical imaging system. In this paper we show
both theoretically and experimentally that, while the resolution in
high-dimensional light-field space is still limited by diffraction, the
statistical spatial resolution of GISC camera can be greatly improved comparing
to classical Rayleigh's criterion by utilizing the discernibility in
high-dimensional light-field space. The interaction between imaging resolution,
degrees of freedom of light field, and degrees of freedom of objects in
high-dimensional light-field space is also demonstrated.
