  Hyperspectral 3D imaging aims to acquire both depth and spectral information
of a scene. However, existing methods are either prohibitively expensive and
bulky or compromise on spectral and depth accuracy. In this work, we present
Dispersed Structured Light (DSL), a cost-effective and compact method for
accurate hyperspectral 3D imaging. DSL modifies a traditional projector-camera
system by placing a sub-millimeter thick diffraction grating film front of the
projector. The grating disperses structured light based on light wavelength. To
utilize the dispersed structured light, we devise a model for dispersive
projection image formation and a per-pixel hyperspectral 3D reconstruction
method. We validate DSL by instantiating a compact experimental prototype. DSL
achieves spectral accuracy of 18.8nm full-width half-maximum (FWHM) and depth
error of 1mm. We demonstrate that DSL outperforms prior work on practical
hyperspectral 3D imaging. DSL promises accurate and practical hyperspectral 3D
imaging for diverse application domains, including computer vision and
graphics, cultural heritage, geology, and biology.
