  We propose DiffuStereo, a novel system using only sparse cameras (8 in this
work) for high-quality 3D human reconstruction. At its core is a novel
diffusion-based stereo module, which introduces diffusion models, a type of
powerful generative models, into the iterative stereo matching network. To this
end, we design a new diffusion kernel and additional stereo constraints to
facilitate stereo matching and depth estimation in the network. We further
present a multi-level stereo network architecture to handle high-resolution (up
to 4k) inputs without requiring unaffordable memory footprint. Given a set of
sparse-view color images of a human, the proposed multi-level diffusion-based
stereo network can produce highly accurate depth maps, which are then converted
into a high-quality 3D human model through an efficient multi-view fusion
strategy. Overall, our method enables automatic reconstruction of human models
with quality on par to high-end dense-view camera rigs, and this is achieved
using a much more light-weight hardware setup. Experiments show that our method
outperforms state-of-the-art methods by a large margin both qualitatively and
quantitatively.
