English

Single-image RGB Photometric Stereo With Spatially-varying Albedo

Computer Vision and Pattern Recognition 2016-09-15 v1

Abstract

We present a single-shot system to recover surface geometry of objects with spatially-varying albedos, from images captured under a calibrated RGB photometric stereo setup---with three light directions multiplexed across different color channels in the observed RGB image. Since the problem is ill-posed point-wise, we assume that the albedo map can be modeled as piece-wise constant with a restricted number of distinct albedo values. We show that under ideal conditions, the shape of a non-degenerate local constant albedo surface patch can theoretically be recovered exactly. Moreover, we present a practical and efficient algorithm that uses this model to robustly recover shape from real images. Our method first reasons about shape locally in a dense set of patches in the observed image, producing shape distributions for every patch. These local distributions are then combined to produce a single consistent surface normal map. We demonstrate the efficacy of the approach through experiments on both synthetic renderings as well as real captured images.

Keywords

Cite

@article{arxiv.1609.04079,
  title  = {Single-image RGB Photometric Stereo With Spatially-varying Albedo},
  author = {Ayan Chakrabarti and Kalyan Sunkavalli},
  journal= {arXiv preprint arXiv:1609.04079},
  year   = {2016}
}

Comments

3DV 2016. Project page at http://www.ttic.edu/chakrabarti/rgbps/