Title
Illumination-invariant Statistical Shape Recovery with Contiguous Occlusion
Abstract
Spherical harmonics (SH) has been an attractive fit for illumination modeling in shape recovery after the conclusion drawn by Basri and Jacobs [1]. The main challenge is the computation of the spherical harmonics projection (SHP) images to be robust against imaging conditions other than illumination. Occlusions due to wearing apparel and makeup, or even incompliance to the requirement of the statistical model introduce errors in the reconstructed SHP images which in turn has a direct impact on the recovered shape. In this paper, we propose to cast errors introduced due to occlusion as: (1) statistical outliers which are determined and rejected using robust statistics and (2) local spatial erroneous continuous regions where Markov Gibbs random field with the homogenous isotropic Potts model is adopted to model the occlusion's spatial interaction. Our results show the effectiveness of the proposed algorithms in handling high levels of contiguous occlusion compared to one of the state-of-the-art statistical illumination invariant shape-from-shading [18]. In particular, MGRF and robust estimation using Geman-McClure function outperform the singular value decomposition (SVD) performance approach which is very sensitive to the presence of occlusion even at low levels. In the meantime, the performance of Lorenztian function approaches SVD due to the presence of errors caused by basis of different identity than the shape to be reconstructed. We provide empirical validation of our conclusions by simulations and real experiments.
Year
DOI
Venue
2011
10.1109/CRV.2011.47
Computer and Robot Vision
Keywords
Field
DocType
contiguous occlusion,statistical model,potts model,shape recovery,robust statistic,illumination modeling,illumination-invariant statistical shape recovery,geman-mcclure function,robust estimation,state-of-the-art statistical illumination invariant,statistical outlier,shape,computer graphics,random field,svd,image reconstruction,shape from shading,spherical harmonics,singular value decomposition,harmonic analysis,robust estimator,markov processes,spherical harmonic,robustness,shp,computer vision,pixel,lighting,computational modeling,robust statistics
Iterative reconstruction,Computer vision,Singular value decomposition,Pattern recognition,Computer science,Spherical harmonics,Outlier,Robust statistics,Robustness (computer science),Artificial intelligence,Statistical model,Invariant (mathematics)
Conference
ISBN
Citations 
PageRank 
978-0-7695-4362-8
1
0.36
References 
Authors
20
4
Name
Order
Citations
PageRank
Shireen Elhabian1142.37
Ham Rara2474.05
Asem Ali3364.69
Aly A. Farag42147172.03