Indoor Scene Reconstruction Using Near-light Photometric Stereo.

We propose a novel framework for photometric stereo (PS) under low-light conditions using uncalibrated nearlight illumination. It operates on free-form video sequences captured with a minimalistic and affordable setup. We address issues such as albedo variations, shadowing, perspective projections and camera noise. Our method uses specular spheres detected with a perspective-correcting Hough transform to robustly triangulate light positions in the presence of outliers via a least-squares approach. Furthermore, we propose an iterative reweighting scheme in combination with an `p-norm minimizer to robustly solve the calibrated near-light PS problem. In contrast to other approaches, our framework reconstructs depth, albedo (relative to light source intensity) and normals simultaneously and is demonstrated on synthetic and real-world scenes.