Filters








41 Hits in 6.0 sec

Robust estimation of surface properties and interpolation of shadow/specularity components

Mark S. Drew, Yacov Hel-Or, Tom Malzbender, Nasim Hajari
2012 Image and Vision Computing  
PTM has two aims: interpolation of images for new lighting directions, and recovery of surface properties.  ...  Here we show that a robust approach is a good deal more accurate in recovering surface properties.  ...  Black dots are Matte+Shadow+Specular luminance; blue circles are non-robust matte LS regression; black crosses are correct matte luminance; and red squares are robust LMS fit.  ... 
doi:10.1016/j.imavis.2012.02.012 fatcat:qgnbxlx2lzfejpyxit2w67s7am

Improving realism of 3D texture using component based modeling

Siddharth Kherada, Prateek Pandey, Anoop M. Namboodiri
2012 2012 IEEE Workshop on the Applications of Computer Vision (WACV)  
We show that the direct and global components of the image have different nature, and when modeled separately, leads to a more accurate and compact model of the 3D surface texture.  ...  This method models sharp shadows and specularities, while preserving the structural relief and surface color.  ...  Each of these components is then further separated to obtain different physical phenomena such as shadows, specularity and luminance.  ... 
doi:10.1109/wacv.2012.6163034 dblp:conf/wacv/KheradaPN12 fatcat:sfrl3owsbngqhic7s4rjat4spa

A Practical Reflectance Transformation Imaging Pipeline For Surface Characterization In Cultural Heritage

Irene Ciortan, Ruggero Pintus, G Marchioro, Claudia Daffara, Andrea Giachetti, Enrico Gobbetti
2016 Zenodo  
An estimation of geometry and reflectance parameters (e.g., albedo, normals, polynomial texture maps coefficients) is then performed to locally characterize surface properties.  ...  The resulting object description is stable and representative enough of surface features to reliably provide a characterization of measured surfaces.  ...  S., HEL-OR Y., MALZBENDER T., HAJARI N.: Robust estimation of surface properties and interpolation of shadow/specularity components. Image and Vision Computing 30, 4 (2012), 317-331. ROUSSEEUW P.  ... 
doi:10.5281/zenodo.177891 fatcat:szouycvsozguxmco7oeu35xywi

Light calibration and quality assessment methods for Reflectance Transformation Imaging applied to artworks' analysis

A. Giachetti, C. Daffara, C. Reghelin, E. Gobbetti, R. Pintus, Luca Pezzati, Piotr Targowski
2015 Optics for Arts, Architecture, and Archaeology V  
way to enrich object visualization into a powerful method for extracting quantitative characterization of surface geometry or of reflective properties of different materials.  ...  small structures and normal estimation, and on samples of different types of paper to evaluate material discrimination.  ...  We are currently developing novel versions of the fitters, also taking into consideration the problem of removing or segmenting projected shadows/specular highlights.  ... 
doi:10.1117/12.2184761 fatcat:osr5enbxyrgnnfe54s2cxtktqm

Augmenting deformable objects in real-time

J. Pilet, V. Lepetit, P. Fua
2005 Fourth IEEE and ACM International Symposium on Mixed and Augmented Reality (ISMAR'05)  
The whole process of uncompressing the video stream, measuring the deformations, estimating the lighting parameters, and realistically augmenting the input image takes about 100 ms on a 2.8 GHz PC.  ...  It is fully automated and does not require any manual initialization or engineering of the scene.  ...  Not only is our approach real-time and fully automated but it also handles complex lighting effects, such as cast shadows, specularities, and multiple light sources of different hues and saturation.  ... 
doi:10.1109/ismar.2005.18 dblp:conf/ismar/PiletLF05 fatcat:qzkvgbzh55f57darluav7txhk4

Real-time surface light-field capture for augmentation of planar specular surfaces

Jan Jachnik, Richard A. Newcombe, Andrew J. Davison
2012 2012 IEEE International Symposium on Mixed and Augmented Reality (ISMAR)  
We then split the light-field into its diffuse and specular components, and show that the specular component can be used for estimation of an environment map.  ...  A new frontier is to work towards recovering the reflectance properties of general surfaces and the lighting configuration in a scene without the need for probes, omnidirectional cameras or specialised  ...  Jachnik, and European Research Council Starting Grant 210346. We are extremely grateful to members of Imperial College's Robot Vision Group for day to day help and collaboration.  ... 
doi:10.1109/ismar.2012.6402544 dblp:conf/ismar/JachnikND12 fatcat:fomy3qpcxjczxiepy3ziwqudnm

Active blobs: region-based, deformable appearance models

Stan Sclaroff, John Isidoro
2003 Computer Vision and Image Understanding  
The approach provides robustness to occlusions, wrinkles, shadows, and specular highlights.  ...  Nonrigid shape registration and motion tracking are achieved by posing the problem as an energy-based, robust minimization procedure.  ...  Department of Education (GAANN).  ... 
doi:10.1016/s1077-3142(03)00003-1 fatcat:sbswvx6rvnasrhr44tcykkwjb4

Toward Reconstructing Surfaces With Arbitrary Isotropic Reflectance : A Stratified Photometric Stereo Approach

Neil G. Alldrin, David J. Kriegman
2007 2007 IEEE 11th International Conference on Computer Vision  
By using additional cues in the image data or imposing additional constraints on the surface (e.g., shadows, specular highlights, Helmholtz Reciprocity, uniform BRDF), the unknown height of each isocontour  ...  can be estimated and the metric structure is resolved.  ...  ., chain-mail) violate our assumptions of isotropy and/or surface differentiability.  ... 
doi:10.1109/iccv.2007.4408881 dblp:conf/iccv/AlldrinK07 fatcat:hmred3qroval7d2s4sjxodetwe

SNeS: Learning Probably Symmetric Neural Surfaces from Incomplete Data [article]

Eldar Insafutdinov, Dylan Campbell, João F. Henriques, Andrea Vedaldi
2022 arXiv   pre-print
To address this, we apply a soft symmetry constraint to the 3D geometry and material properties, having factored appearance into lighting, albedo colour and reflectivity.  ...  We build on the strengths of recent advances in neural reconstruction and rendering such as Neural Radiance Fields (NeRF).  ...  effects (shadows, specularity, and reflections), which are not symmetric.  ... 
arXiv:2206.06340v1 fatcat:z36e4ay7mnarfggcxmawhgxu6u

Learning object representations from lighting variations [chapter]

R. Epstein, A. L. Yuille, P. N. Belhumeur
1996 Lecture Notes in Computer Science  
We discuss several models of learning object representations...  ...  10 Acknowledgments* Support was provided by NSF Grant IRI 92-23676 and ARPA/ONR Contract N00014-95-1-1022. We thank David Mumford, Dan Kersten, David Kriegman and Mike T arr for helpful discussions.  ...  Thus we need a method which can estimate them and the surface properties simultaneously.  ... 
doi:10.1007/3-540-61750-7_29 fatcat:kvexq7357rgszfc64pwrp6u4l4

Modeling Bidirectional Texture Functions with Multivariate Spherical Radial Basis Functions

Yu-Ting Tsai, Kuei-Li Fang, Wen-Chieh Lin, Zen-Chung Shih
2011 IEEE Transactions on Pattern Analysis and Machine Intelligence  
First, since the surface appearance of a real-world object is frequently a mixed effect of different physical factors, the proposed sum-of-products model based on multivariate SRBFs especially provides  ...  an intrinsic and efficient representation for heterogenous materials.  ...  This work was supported in part by the National Science Council of Taiwan under Grant No. NSC96-2221-E-009-152-MY3, NSC99-2628-E-009-178, and NSC100-2218-E-155-002.  ... 
doi:10.1109/tpami.2010.211 pmid:21135438 fatcat:gy27xmnzbbgyld6alt4g4ifnee

Local Spherical Harmonics for Facial Shape and Albedo Estimation

Suwoong Heo, Hyewon Song, Jiwoo Kang, Sanghoon Lee
2020 IEEE Access  
However, when a facial image is captured in an unconstrained scene, the illumination is inappropriately estimated due to the presence of shadow and specular reflections.  ...  For accurate estimation of albedo, we also utilize facial albedo statistics to prevent the estimated albedo from becoming biased toward input image.  ...  Although the second-order SH is proven to be robust for Lambertian diffuse surfaces [19] , facial images in natural scenes contain various lighting effects such as cast shadow, specular, and indirect  ... 
doi:10.1109/access.2020.3026545 fatcat:cudfupva7bcwjawlih2xjf7kau

Single Day Outdoor Photometric Stereo [article]

Yannick Hold-Geoffroy, Paulo F.U. Gotardo, Jean-François Lalonde
2019 arXiv   pre-print
Given a sequence of outdoor images captured during a single sunny day, our method robustly estimates the scene surface normals with unprecedented quality for the considered scenario.  ...  Second, we solve the ambiguity arising in clear days by combining photometric cues with prior knowledge on material properties, local surface geometry and the natural variations in outdoor lighting through  ...  The method is robust to shadows, specularities and arbitrary but spatially uniform albedo.  ... 
arXiv:1803.10850v3 fatcat:n4ucn7xefjcxfmb6nnqfvlkzkm

A neural fuzzy system for image motion estimation

C.T. Lin, I.F. Chung, L.K.Martin Sheu
2000 Fuzzy sets and systems (Print)  
This system is more reliable, robust, and accurate in motion estimation than many other methods including Horn and Schunck's optical ow, fuzzy logic motion estimator (FME), best block matching, NR, and  ...  As a summary, the signiÿcant characteristics of the proposed system include that it is more robust than several previous methods; it can estimate motion vector more accurately than several other methods  ...  The goal is to compute an approximation to the 2-D motion ÿeld -a projection of the 3-D velocities of surface points onto the imaging surface.  ... 
doi:10.1016/s0165-0114(99)00075-5 fatcat:jgu3ykkkjbdn3hyvvqo275twhy

A gentle introduction to bilateral filtering and its applications

Sylvain Paris, Pierre Kornprobst, Jack Tumblin, Frédo Durand
2008 ACM SIGGRAPH 2008 classes on - SIGGRAPH '08  
This work was supported in part by the Israel Science Foundation founded by the Israel Academy of Sciences and Humanities, and by the Israeli Ministry of Science, and by a grant from the German Israel  ...  Analysis and Transfer of Pictorial Style," and a grant from Acknowledgments We would like to thank Byong Mok Oh for his help with the radiance maps and the bibliography; he and Ray Jones also provided  ...  Also note that the flash shadow/specularity detection algorithm properly masks out the large specular highlight on the brown pot and does not transfer that detail to the final image. counter-example, this  ... 
doi:10.1145/1401132.1401134 dblp:conf/siggraph/ParisKTD08 fatcat:czf26lysxzadvhr2vtgltfozxu
« Previous Showing results 1 — 15 out of 41 results