Shape and photometric invariants recovery from polarisation images

Abstract

The disclosure concerns processing of electronic images, such as hyperspectral, or multispectral images. In particular, but is not limited to, a method, software and computer for estimating shape information or a photometric invariant of a location of image of a scene. The image data () indexed by wavelength λ and polarization filter angle θ. For each wavelength λ index, a polarization angle φ is estimated from the image data () by the processor (). The processor () then also estimates the shape information (such as azimuth α, such as zenith θ, or surface normal) or photometric invariants (such as refractive index) based on the estimated polarization angle φ for each wavelength index λ. Greater accuracies can be achieved in the estimated shape information and/or photometric invariants by using wavelength-indexed data. Further, surface information or photometric invariant can be estimated based upon polarization in a single-view hyperspectral or multi-spectral imagery. Further, by relying on the polarization angle for the estimation, the method is insensitive to changes in illumination power and direction.