Lost but Found? Harnessing the Internet for Photometric Completion

While it is important to digitize heritage sites ‘as is’, building 3D models of damaged archaeological structures can be visually unpleasant due to the presence of large miss-ing regions. This work addresses intensity filling-in, or in-tensity inpainting, of such large damaged regions post ge-ometric reconstruction. Assuming a Lambertian image for-mation model, we first establish that patches corresponding to arbitrarily oriented planar regions found in internet im-ages of several archaeological structures with possibly dif-ferent albedo and observed under varied and uncontrolled illumination lie in a low-dimensional subspace. These are then used for inpainting by modeling the missing region as gross pixel corruptions. The performance of the proposed method along with comparisons are shown on synthetic as well as real data. 1