A sparse representation method for determining the optimal illumination directions in Photometric Stereo

• The optimal illumination configuration for Photometric Stereo.
• A sparse representation of the illumination using l1 optimisation was considered.
• A hemisphere structure for the sampled lights was considered.
• The Lambertian model was considered.
• Experiments were performed with real and synthetic data to verify the outcomes.

The analysis of surface and texture details with the help of changes in illumination direction is a key task in 3D shape reconstruction either based on Photometric Stereo, Shape from Shading or Structured Light. This paper presents a novel approach for estimating the optimal illumination directions for the accurate calculation of the surface normals, while minimising the presence of shadows and the reconstructed albedo error. The method regards a sparse representation of the illumination arrangement and estimates the light directions using l1 optimisation. The Lambertian model is considered and the theoretical development is demonstrated with experimental results.