  In conventional point cloud delivery, a sender uses octree-based digital
video compression to stream three-dimensional (3D) points and the corresponding
color attributes over band-limited links, e.g., wireless channels, for 3D scene
reconstructions. However, the digital-based delivery schemes have an issue
called cliff effect, where the 3D reconstruction quality is a step function in
terms of wireless channel quality. We propose a novel scheme of point cloud
delivery, called HoloCast, to gracefully improve the reconstruction quality
with the improvement of wireless channel quality. HoloCast regards the 3D
points and color components as graph signals and directly transmits
linear-transformed signals based on graph Fourier transform (GFT), without
digital quantization and entropy coding operations. One of main contributions
in HoloCast is that the use of GFT can deal with non-ordered and non-uniformly
distributed multi-dimensional signals such as holographic data unlike
conventional delivery schemes. Performance results with point cloud data show
that HoloCast yields better 3D reconstruction quality compared to digital-based
methods in noisy wireless environment.
