  Non-line-of-sight (NLOS) imaging enables the visualization of objects hidden
from direct view, with applications in surveillance, remote sensing, and light
detection and ranging. Here, we introduce a NLOS imaging technique termed
ptychographic NLOS (pNLOS), which leverages coded ptychography for
depth-resolved imaging of obscured objects. Our approach involves scanning a
laser spot on a wall to illuminate the hidden objects in an obscured region.
The reflected wavefields from these objects then travel back to the wall, get
modulated by the wall's complex-valued profile, and the resulting diffraction
patterns are captured by a camera. By modulating the object wavefields, the
wall surface serves the role of the coded layer as in coded ptychography. As we
scan the laser spot to different positions, the reflected object wavefields on
the wall translate accordingly, with the shifts varying for objects at
different depths. This translational diversity enables the acquisition of a set
of modulated diffraction patterns referred to as a ptychogram. By processing
the ptychogram, we recover both the objects at different depths and the
modulation profile of the wall surface. Experimental results demonstrate
high-resolution, high-fidelity imaging of hidden objects, showcasing the
potential of pNLOS for depth-aware vision beyond the direct line of sight.
