  Recently introduced angular-memory-effect based techniques enable
non-invasive imaging of objects hidden behind thin scattering layers. However,
both the speckle-correlation and the bispectrum analysis are based on the
statistical average of large amounts of speckle grains, which determines that
they can hardly access the important information of the point-spread-function
(PSF) of a highly scattering imaging system. Here, inspired by notions used in
astronomy, we present a phase-diversity speckle imaging scheme, based on
recording a sequence of intensity speckle patterns at various imaging planes,
and experimentally demonstrate that in addition to being able to retrieve
diffraction-limited image of hidden objects, phase-diversity can also
simultaneously estimate the pupil function and the PSF of a highly scattering
imaging system without any guide-star nor reference.
