PI-NLOS: polarized infrared non-line-of-sight imaging

Passive non-line-of-sight (NLOS) imaging is a promising technique to enhance visual perception for the occluded object hidden behind the wall. Here we present a data-driven NLOS imaging framework by using polarization cue and long-wavelength infrared (LWIR) images. We design a dual-channel input deep neural network to fuse the intensity features from polarized LWIR images and contour features from polarization degree images for NLOS scene reconstruction. To train the model, we create a polarized LWIR NLOS dataset which contains over ten thousand images. The paper demonstrates the passive NLOS imaging experiment in which the hidden people is approximate 6 meters away from the relay wall. It is an exciting finding that even the range is further than that in the prior works. The quantitative evaluation metric of PSNR and SSIM show that our method as an advance over state-of-the-art in passive NLOS imaging.