35-Issue 7

Permanent URI for this collection

Matching and Interpolation
Geometrically Based Linear Iterative Clustering for Quantitative Feature Correspondence
Qingan Yan, Long Yang, Chao Liang, Huajun Liu, Ruimin Hu, and Chunxia Xiao
An Eulerian Approach for Constructing a Map Between Surfaces With Different Topologies
Hangil Park, Youngjin Cho, Seungbae Bang, and Sung-Hee Lee
Spatial Matching of Animated Meshes
Hyewon Seo and Frederic Cordier
Retargeting 3D Objects and Scenes with a General Framework
Chun-Kai Huang, Yi-Ling Chen, I-Chao Shen, and Bing-Yu Chen
Planar Shape Interpolation Based On Teichmüller Mapping
Xianshun Nian and Falai Chen
Textures/Mapping
An Efficient Structure-Aware Bilateral Texture Filtering for Image Smoothing
Ting-Hao Lin, Der-Lor Way, Zen-Chung Shih, Wen-Kai Tai, and Chin-Chen Chang
Programmable Animation Texturing using Motion Stamps
Antoine Milliez, Martin Guay, Marie-Paule Cani, Markus Gross, and Robert W. Sumner
Scale-aware Structure-Preserving Texture Filtering
Junho Jeon, Hyunjoon Lee, Henry Kang, and Seungyong Lee
Real-time Texture Synthesis and Concurrent Random-access Rendering for Low-cost GPU Chip Design
Linling Zhang, Simon Fenney, and Fernando Escribano
Efficient Volumetric PolyCube-Map Construction
Xiao-Ming Fu, Chong-Yang Bai, and Yang Liu
Visualization/NPR
Trip Synopsis: 60km in 60sec
Hui Huang, Dani Lischinski, Zhuming Hao, Minglun Gong, Marc Christie, and Daniel Cohen-Or
A Study On Designing Effective Introductory Materials for Information Visualization
Yuzuru Tanahashi, Nick Leaf, and Kwan-Liu Ma
Aesthetic Rating and Color Suggestion for Color Palettes
Naoki Kita and Kazunori Miyata
Temporally Coherent and Artistically Intended Stylization of Feature Lines Extracted from 3D Models
Luis Cardona and Suguru Saito
Reconstruction
3D Body Shapes Estimation from Dressed-Human Silhouettes
Dan Song, Ruofeng Tong, Jian Chang, Xiaosong Yang, Min Tang, and Jian Jun Zhang
Piecewise Smooth Reconstruction of Normal Vector Field on Digital Data
David Coeurjolly, Marion Foare, Pierre Gueth, and Jacques-Olivier Lachaud
Incremental Deformation Subspace Reconstruction
Rajaditya Mukherjee, Xiaofeng Wu, and Huamin Wang
Piecewise-planar Reconstruction of Multi-room Interiors with Arbitrary Wall Arrangements
Claudio Mura, Oliver Mattausch, and Renato Pajarola
Image Processing
Appearance Harmonization for Single Image Shadow Removal
Li-Qian Ma, Jue Wang, Eli Shechtman, Kalyan Sunkavalli, and Shi-Min Hu
Anisotropic Superpixel Generation Based on Mahalanobis Distance
Yiqi Cai and Xiaohu Guo
Image Recoloring with Valence-Arousal Emotion Model
Hye-Rin Kim, Henry Kang, and In-Kwon Lee
Non-Local Sparse and Low-Rank Regularization for Structure-Preserving Image Smoothing
Lei Zhu, Chi-Wing Fu, Yueming Jin, Mingqiang Wei, Jing Qin, and Pheng-Ann Heng
Re-Compositable Panoramic Selfie with Robust Multi-Frame Segmentation and Stitching
Kai Li, Jue Wang, Yebin Liu, Li Xu, and Qionghai Dai
Modeling
Skeleton-driven Adaptive Hexahedral Meshing of Tubular Shapes
Marco Livesu, Alessandro Muntoni, Enrico Puppo, and Riccardo Scateni
Flow Curves: an Intuitive Interface for Coherent Scene Deformation
Loïc Ciccone, Martin Guay, and Robert W. Sumner
Efficient Modeling of Entangled Details for Natural Scenes
Eric Guérin, Eric Galin, François Grosbellet, Adrien Peytavie, and Jean-David Génevaux
Automatic Modeling of Urban Facades from Raw LiDAR Point Data
Jun Wang, Yabin Xu, Oussama Remil, Xingyu Xie, Nan Ye, and Mingqiang Wei
Ray Tracing/Appearance Capture
TSS BVHs: Tetrahedron Swept Sphere BVHs for Ray Tracing Subdivision Surfaces
Peng Du, Yong-Jun Kim, and Sung Eui Yoon
Foveated Real-Time Ray Tracing for Head-Mounted Displays
Martin Weier, Thorsten Roth, Ernst Kruijff, André Hinkenjann, Arsène Pérard-Gayot, Philipp Slusallek, and Yongmin Li
Minimal Sampling for Effective Acquisition of Anisotropic BRDFs
Radomir Vávra and Jiri Filip
Fabrication
Adaptive Bas-relief Generation from 3D Object under Illumination
Yu-Wei Zhang, Caiming Zhang, Wenping Wang, and Yanzhao Chen
An Interactive Design System of Free-Formed Bamboo-Copters
Morihiro Nakamura, Yuki Koyama, Daisuke Sakamoto, and Takeo Igarashi
Direct Shape Optimization for Strengthening 3D Printable Objects
Yahan Zhou, Evangelos Kalogerakis, Rui Wang, and Ian R. Grosse
Anaglyph Caustics with Motion Parallax
Marcel Lancelle, Tobias Martin, Barbara Solenthaler, and Markus Gross
Efficient Rendering
Proxy-guided Image-based Rendering for Mobile Devices
Bernhard Reinert, Johannes Kopf, Tobias Ritschel, Eduardo Cuervo, David Chu, and Hans-Peter Seidel
Pixel History Linear Models for Real-Time Temporal Filtering
Jose A. Iglesias-Guitian, Bochang Moon, Charalampos Koniaris, Eric Smolikowski, and Kenny Mitchell
Multiple Scattering Approximation in Heterogeneous Media by Narrow Beam Distributions
Mikio Shinya, Yoshinori Dobashi, Michio Shiraishi, Motonobu Kawashima, and Tomoyuki Nishita
Merged Multiresolution Hierarchies for Shadow Map Compression
Leonardo Scandolo, Pablo Bauszat, and Elmar Eisemann
Images and Video
Facial Feature Exaggeration According to Social Psychology of Face Perception
Lihui Tian and Shuangjiu Xiao
Efficient Multi-image Correspondences for On-line Light Field Video Processing
Łukasz Dąbała, Matthias Ziegler, Piotr Didyk, Frederik Zilly, Joachim Keinert, Karol Myszkowski, Hans-Peter Seidel, Przemysław Rokita, and Tobias Ritschel
Feature-Aware Pixel Art Animation
Ming-Hsun Kuo, Yong-Liang Yang, and Hung-Kuo Chu
Physically Based Video Editing
Jean-Charles Bazin, Claudia Plüss (Kuster), Guo Yu, Tobias Martin, Alec Jacobson, and Markus Gross
Realistic Rendering
An Error Estimation Framework for Many-Light Rendering
Kosuke Nabata, Kei Iwasaki, Yoshinori Dobashi, and Tomoyuki Nishita
Decoupled Space and Time Sampling of Motion and Defocus Blur for Unified Rendering of Transparent and Opaque Objects
Sven Widmer, Dominik Wodniok, Daniel Thul, Stefan Guthe, and Michael Goesele
Variance Analysis of Multi-sample and One-sample Multiple Importance Sampling
Mateu Sbert, Vlastimil Havran, and Laszlo Szirmay-Kalos
Reduced Aggregate Scattering Operators for Path Tracing
Adrian Blumer, Jan Novák, Ralf Habel, Derek Nowrouzezahrai, and Wojciech Jarosz
Geometry
Progressive Compression of Arbitrary Textured Meshes
Florian Caillaud, Vincent Vidal, Florent Dupont, and Guillaume Lavoué
Tracing Field-Coherent Quad Layouts
Nico Pietroni, Enrico Puppo, Giorgio Marcias, Roberto Scopigno, and Paolo Cignoni
Visual Contrast Sensitivity and Discrimination for 3D Meshes and their Applications
Georges Nader, Kai Wang, Franck Hétroy-Wheeler, and Florent Dupont
Harmonic Functions for Rotational Symmetry Vector Fields
Zhongwei Shen, Xianzhong Fang, Xinguo Liu, Hujun Bao, and Jin Huang
Fluids
A Multilevel SPH Solver with Unified Solid Boundary Handling
Tetsuya Takahashi and Ming C. Lin

BibTeX (35-Issue 7)
                
@article{
10.1111:cgf.13000,
journal = {Computer Graphics Forum}, title = {{
Spatial Matching of Animated Meshes}},
author = {
Seo, Hyewon
and
Cordier, Frederic
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13000}
}
                
@article{
10.1111:cgf.12998,
journal = {Computer Graphics Forum}, title = {{
Geometrically Based Linear Iterative Clustering for Quantitative Feature Correspondence}},
author = {
Yan, Qingan
and
Yang, Long
and
Liang, Chao
and
Liu, Huajun
and
Hu, Ruimin
and
Xiao, Chunxia
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12998}
}
                
@article{
10.1111:cgf.12999,
journal = {Computer Graphics Forum}, title = {{
An Eulerian Approach for Constructing a Map Between Surfaces With Different Topologies}},
author = {
Park, Hangil
and
Cho, Youngjin
and
Bang, Seungbae
and
Lee, Sung-Hee
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12999}
}
                
@article{
10.1111:cgf.13001,
journal = {Computer Graphics Forum}, title = {{
Retargeting 3D Objects and Scenes with a General Framework}},
author = {
Huang, Chun-Kai
and
Chen, Yi-Ling
and
Shen, I-Chao
and
Chen, Bing-Yu
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13001}
}
                
@article{
10.1111:cgf.13002,
journal = {Computer Graphics Forum}, title = {{
Planar Shape Interpolation Based On Teichmüller Mapping}},
author = {
Nian, Xianshun
and
Chen, Falai
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13002}
}
                
@article{
10.1111:cgf.13003,
journal = {Computer Graphics Forum}, title = {{
An Efficient Structure-Aware Bilateral Texture Filtering for Image Smoothing}},
author = {
Lin, Ting-Hao
and
Way, Der-Lor
and
Shih, Zen-Chung
and
Tai, Wen-Kai
and
Chang, Chin-Chen
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13003}
}
                
@article{
10.1111:cgf.13004,
journal = {Computer Graphics Forum}, title = {{
Programmable Animation Texturing using Motion Stamps}},
author = {
Milliez, Antoine
and
Guay, Martin
and
Cani, Marie-Paule
and
Gross, Markus
and
Sumner, Robert W.
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13004}
}
                
@article{
10.1111:cgf.13005,
journal = {Computer Graphics Forum}, title = {{
Scale-aware Structure-Preserving Texture Filtering}},
author = {
Jeon, Junho
and
Lee, Hyunjoon
and
Kang, Henry
and
Lee, Seungyong
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13005}
}
                
@article{
10.1111:cgf.13006,
journal = {Computer Graphics Forum}, title = {{
Real-time Texture Synthesis and Concurrent Random-access Rendering for Low-cost GPU Chip Design}},
author = {
Zhang, Linling
and
Fenney, Simon
and
Escribano, Fernando
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13006}
}
                
@article{
10.1111:cgf.13007,
journal = {Computer Graphics Forum}, title = {{
Efficient Volumetric PolyCube-Map Construction}},
author = {
Fu, Xiao-Ming
and
Bai, Chong-Yang
and
Liu, Yang
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13007}
}
                
@article{
10.1111:cgf.13008,
journal = {Computer Graphics Forum}, title = {{
Trip Synopsis: 60km in 60sec}},
author = {
Huang, Hui
and
Lischinski, Dani
and
Hao, Zhuming
and
Gong, Minglun
and
Christie, Marc
and
Cohen-Or, Daniel
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13008}
}
                
@article{
10.1111:cgf.13009,
journal = {Computer Graphics Forum}, title = {{
A Study On Designing Effective Introductory Materials for Information Visualization}},
author = {
Tanahashi, Yuzuru
and
Leaf, Nick
and
Ma, Kwan-Liu
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13009}
}
                
@article{
10.1111:cgf.13010,
journal = {Computer Graphics Forum}, title = {{
Aesthetic Rating and Color Suggestion for Color Palettes}},
author = {
Kita, Naoki
and
Miyata, Kazunori
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13010}
}
                
@article{
10.1111:cgf.13011,
journal = {Computer Graphics Forum}, title = {{
Temporally Coherent and Artistically Intended Stylization of Feature Lines Extracted from 3D Models}},
author = {
Cardona, Luis
and
Saito, Suguru
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13011}
}
                
@article{
10.1111:cgf.13012,
journal = {Computer Graphics Forum}, title = {{
3D Body Shapes Estimation from Dressed-Human Silhouettes}},
author = {
Song, Dan
and
Tong, Ruofeng
and
Chang, Jian
and
Yang, Xiaosong
and
Tang, Min
and
Zhang, Jian Jun
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13012}
}
                
@article{
10.1111:cgf.13013,
journal = {Computer Graphics Forum}, title = {{
Piecewise Smooth Reconstruction of Normal Vector Field on Digital Data}},
author = {
Coeurjolly, David
and
Foare, Marion
and
Gueth, Pierre
and
Lachaud, Jacques-Olivier
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13013}
}
                
@article{
10.1111:cgf.13014,
journal = {Computer Graphics Forum}, title = {{
Incremental Deformation Subspace Reconstruction}},
author = {
Mukherjee, Rajaditya
and
Wu, Xiaofeng
and
Wang, Huamin
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13014}
}
                
@article{
10.1111:cgf.13015,
journal = {Computer Graphics Forum}, title = {{
Piecewise-planar Reconstruction of Multi-room Interiors with Arbitrary Wall Arrangements}},
author = {
Mura, Claudio
and
Mattausch, Oliver
and
Pajarola, Renato
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13015}
}
                
@article{
10.1111:cgf.13016,
journal = {Computer Graphics Forum}, title = {{
Appearance Harmonization for Single Image Shadow Removal}},
author = {
Ma, Li-Qian
and
Wang, Jue
and
Shechtman, Eli
and
Sunkavalli, Kalyan
and
Hu, Shi-Min
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13016}
}
                
@article{
10.1111:cgf.13017,
journal = {Computer Graphics Forum}, title = {{
Anisotropic Superpixel Generation Based on Mahalanobis Distance}},
author = {
Cai, Yiqi
and
Guo, Xiaohu
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13017}
}
                
@article{
10.1111:cgf.13018,
journal = {Computer Graphics Forum}, title = {{
Image Recoloring with Valence-Arousal Emotion Model}},
author = {
Kim, Hye-Rin
and
Kang, Henry
and
Lee, In-Kwon
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13018}
}
                
@article{
10.1111:cgf.13019,
journal = {Computer Graphics Forum}, title = {{
Non-Local Sparse and Low-Rank Regularization for Structure-Preserving Image Smoothing}},
author = {
Zhu, Lei
and
Fu, Chi-Wing
and
Jin, Yueming
and
Wei, Mingqiang
and
Qin, Jing
and
Heng, Pheng-Ann
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13019}
}
                
@article{
10.1111:cgf.13021,
journal = {Computer Graphics Forum}, title = {{
Skeleton-driven Adaptive Hexahedral Meshing of Tubular Shapes}},
author = {
Livesu, Marco
and
Muntoni, Alessandro
and
Puppo, Enrico
and
Scateni, Riccardo
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13021}
}
                
@article{
10.1111:cgf.13020,
journal = {Computer Graphics Forum}, title = {{
Re-Compositable Panoramic Selfie with Robust Multi-Frame Segmentation and Stitching}},
author = {
Li, Kai
and
Wang, Jue
and
Liu, Yebin
and
Xu, Li
and
Dai, Qionghai
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13020}
}
                
@article{
10.1111:cgf.13022,
journal = {Computer Graphics Forum}, title = {{
Flow Curves: an Intuitive Interface for Coherent Scene Deformation}},
author = {
Ciccone, Loïc
and
Guay, Martin
and
Sumner, Robert W.
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13022}
}
                
@article{
10.1111:cgf.13023,
journal = {Computer Graphics Forum}, title = {{
Efficient Modeling of Entangled Details for Natural Scenes}},
author = {
Guérin, Eric
and
Galin, Eric
and
Grosbellet, François
and
Peytavie, Adrien
and
Génevaux, Jean-David
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13023}
}
                
@article{
10.1111:cgf.13024,
journal = {Computer Graphics Forum}, title = {{
Automatic Modeling of Urban Facades from Raw LiDAR Point Data}},
author = {
Wang, Jun
and
Xu, Yabin
and
Remil, Oussama
and
Xie, Xingyu
and
Ye, Nan
and
Wei, Mingqiang
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13024}
}
                
@article{
10.1111:cgf.13025,
journal = {Computer Graphics Forum}, title = {{
TSS BVHs: Tetrahedron Swept Sphere BVHs for Ray Tracing Subdivision Surfaces}},
author = {
Du, Peng
and
Kim, Yong-Jun
and
Yoon, Sung Eui
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13025}
}
                
@article{
10.1111:cgf.13026,
journal = {Computer Graphics Forum}, title = {{
Foveated Real-Time Ray Tracing for Head-Mounted Displays}},
author = {
Weier, Martin
and
Roth, Thorsten
and
Kruijff, Ernst
and
Hinkenjann, André
and
Pérard-Gayot, Arsène
and
Slusallek, Philipp
and
Li, Yongmin
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13026}
}
                
@article{
10.1111:cgf.13027,
journal = {Computer Graphics Forum}, title = {{
Minimal Sampling for Effective Acquisition of Anisotropic BRDFs}},
author = {
Vávra, Radomir
and
Filip, Jiri
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13027}
}
                
@article{
10.1111:cgf.13028,
journal = {Computer Graphics Forum}, title = {{
Adaptive Bas-relief Generation from 3D Object under Illumination}},
author = {
Zhang, Yu-Wei
and
Zhang, Caiming
and
Wang, Wenping
and
Chen, Yanzhao
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13028}
}
                
@article{
10.1111:cgf.13029,
journal = {Computer Graphics Forum}, title = {{
An Interactive Design System of Free-Formed Bamboo-Copters}},
author = {
Nakamura, Morihiro
and
Koyama, Yuki
and
Sakamoto, Daisuke
and
Igarashi, Takeo
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13029}
}
                
@article{
10.1111:cgf.13030,
journal = {Computer Graphics Forum}, title = {{
Direct Shape Optimization for Strengthening 3D Printable Objects}},
author = {
Zhou, Yahan
and
Kalogerakis, Evangelos
and
Wang, Rui
and
Grosse, Ian R.
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13030}
}
                
@article{
10.1111:cgf.13031,
journal = {Computer Graphics Forum}, title = {{
Anaglyph Caustics with Motion Parallax}},
author = {
Lancelle, Marcel
and
Martin, Tobias
and
Solenthaler, Barbara
and
Gross, Markus
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13031}
}
                
@article{
10.1111:cgf.13032,
journal = {Computer Graphics Forum}, title = {{
Proxy-guided Image-based Rendering for Mobile Devices}},
author = {
Reinert, Bernhard
and
Kopf, Johannes
and
Ritschel, Tobias
and
Cuervo, Eduardo
and
Chu, David
and
Seidel, Hans-Peter
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13032}
}
                
@article{
10.1111:cgf.13033,
journal = {Computer Graphics Forum}, title = {{
Pixel History Linear Models for Real-Time Temporal Filtering}},
author = {
Iglesias-Guitian, Jose A.
and
Moon, Bochang
and
Koniaris, Charalampos
and
Smolikowski, Eric
and
Mitchell, Kenny
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13033}
}
                
@article{
10.1111:cgf.13034,
journal = {Computer Graphics Forum}, title = {{
Multiple Scattering Approximation in Heterogeneous Media by Narrow Beam Distributions}},
author = {
Shinya, Mikio
and
Dobashi, Yoshinori
and
Shiraishi, Michio
and
Kawashima, Motonobu
and
Nishita, Tomoyuki
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13034}
}
                
@article{
10.1111:cgf.13035,
journal = {Computer Graphics Forum}, title = {{
Merged Multiresolution Hierarchies for Shadow Map Compression}},
author = {
Scandolo, Leonardo
and
Bauszat, Pablo
and
Eisemann, Elmar
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13035}
}
                
@article{
10.1111:cgf.13036,
journal = {Computer Graphics Forum}, title = {{
Facial Feature Exaggeration According to Social Psychology of Face Perception}},
author = {
Tian, Lihui
and
Xiao, Shuangjiu
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13036}
}
                
@article{
10.1111:cgf.13037,
journal = {Computer Graphics Forum}, title = {{
Efficient Multi-image Correspondences for On-line Light Field Video Processing}},
author = {
Dąbała, Łukasz
and
Ziegler, Matthias
and
Didyk, Piotr
and
Zilly, Frederik
and
Keinert, Joachim
and
Myszkowski, Karol
and
Seidel, Hans-Peter
and
Rokita, Przemysław
and
Ritschel, Tobias
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13037}
}
                
@article{
10.1111:cgf.13039,
journal = {Computer Graphics Forum}, title = {{
Physically Based Video Editing}},
author = {
Bazin, Jean-Charles
and
Plüss (Kuster), Claudia
and
Yu, Guo
and
Martin, Tobias
and
Jacobson, Alec
and
Gross, Markus
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13039}
}
                
@article{
10.1111:cgf.13038,
journal = {Computer Graphics Forum}, title = {{
Feature-Aware Pixel Art Animation}},
author = {
Kuo, Ming-Hsun
and
Yang, Yong-Liang
and
Chu, Hung-Kuo
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13038}
}
                
@article{
10.1111:cgf.13040,
journal = {Computer Graphics Forum}, title = {{
An Error Estimation Framework for Many-Light Rendering}},
author = {
Nabata, Kosuke
and
Iwasaki, Kei
and
Dobashi, Yoshinori
and
Nishita, Tomoyuki
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13040}
}
                
@article{
10.1111:cgf.13041,
journal = {Computer Graphics Forum}, title = {{
Decoupled Space and Time Sampling of Motion and Defocus Blur for Unified Rendering of Transparent and Opaque Objects}},
author = {
Widmer, Sven
and
Wodniok, Dominik
and
Thul, Daniel
and
Guthe, Stefan
and
Goesele, Michael
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13041}
}
                
@article{
10.1111:cgf.13042,
journal = {Computer Graphics Forum}, title = {{
Variance Analysis of Multi-sample and One-sample Multiple Importance Sampling}},
author = {
Sbert, Mateu
and
Havran, Vlastimil
and
Szirmay-Kalos, Laszlo
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13042}
}
                
@article{
10.1111:cgf.13043,
journal = {Computer Graphics Forum}, title = {{
Reduced Aggregate Scattering Operators for Path Tracing}},
author = {
Blumer, Adrian
and
Novák, Jan
and
Habel, Ralf
and
Nowrouzezahrai, Derek
and
Jarosz, Wojciech
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13043}
}
                
@article{
10.1111:cgf.13044,
journal = {Computer Graphics Forum}, title = {{
Progressive Compression of Arbitrary Textured Meshes}},
author = {
Caillaud, Florian
and
Vidal, Vincent
and
Dupont, Florent
and
Lavoué, Guillaume
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13044}
}
                
@article{
10.1111:cgf.13045,
journal = {Computer Graphics Forum}, title = {{
Tracing Field-Coherent Quad Layouts}},
author = {
Pietroni, Nico
and
Puppo, Enrico
and
Marcias, Giorgio
and
Scopigno, Roberto
and
Cignoni, Paolo
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13045}
}
                
@article{
10.1111:cgf.13046,
journal = {Computer Graphics Forum}, title = {{
Visual Contrast Sensitivity and Discrimination for 3D Meshes and their Applications}},
author = {
Nader, Georges
and
Wang, Kai
and
Hétroy-Wheeler, Franck
and
Dupont, Florent
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13046}
}
                
@article{
10.1111:cgf.13047,
journal = {Computer Graphics Forum}, title = {{
Harmonic Functions for Rotational Symmetry Vector Fields}},
author = {
Shen, Zhongwei
and
Fang, Xianzhong
and
Liu, Xinguo
and
Bao, Hujun
and
Huang, Jin
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13047}
}
                
@article{
10.1111:cgf.13048,
journal = {Computer Graphics Forum}, title = {{
A Multilevel SPH Solver with Unified Solid Boundary Handling}},
author = {
Takahashi, Tetsuya
and
Lin, Ming C.
}, year = {
2016},
publisher = {
The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.13048}
}

Browse

Recent Submissions

Now showing 1 - 52 of 52
  • Item
    PG 2016: Frontmatter
    (Eurographics Association, 2016) Eitan Grinspun; Bernd Bickel; Yoshinori Dobashi;
  • Item
    Spatial Matching of Animated Meshes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Seo, Hyewon; Cordier, Frederic; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    This paper presents a new technique which makes use of deformation and motion properties between animated meshes for finding their spatial correspondences. Given a pair of animated meshes exhibiting a semantically similar motion, we compute a sparse set of feature points on each mesh and compute spatial correspondences among them so that points with similar motion behavior are put in correspondence. At the core of our technique is our new, dynamic feature descriptor named AnimHOG, which encodes local deformation characteristics. AnimHOG is ob-tained by computing the gradient of a scalar field inside the spatiotemporal neighborhood of a point of interest, where the scalar values are obtained from the deformation characteristic associated with each vertex and at each frame. The final matching has been formulated as a discreet optimization problem that finds the matching of each feature point on the source mesh so that the descriptor similarity between the corresponding feature pairs as well as compatibility and consistency as measured across the pairs of correspondences are maximized. Consequently, reliable correspondences can be found even among the meshes of very different shape, as long as their motions are similar. We demonstrate the performance of our technique by showing the good quality of matching results we obtained on a number of animated mesh pairs.
  • Item
    Geometrically Based Linear Iterative Clustering for Quantitative Feature Correspondence
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Yan, Qingan; Yang, Long; Liang, Chao; Liu, Huajun; Hu, Ruimin; Xiao, Chunxia; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    A major challenge in feature matching is the lack of objective criteria to determine corresponding points. Recent methods find match candidates first by exploring the proximity in descriptor space, and then rely on a ratio-test strategy to determine final correspondences. However, these measurements are heuristic and subjectively excludes massive true positive correspondences that should be matched. In this paper, we propose a novel feature matching algorithm for image collections, which is capable of providing quantitative depiction to the plausibility of feature matches. We achieve this by exploring the epipolar consistency between feature points and their potential correspondences, and reformulate feature matching as an optimization problem in which the overall geometric inconsistency across the entire image set ought to be minimized. We derive the solution of the optimization problem in a simple linear iterative manner, where a k-means-type approach is designed to automatically generate consistent feature clusters. Experiments show that our method produces precise correspondences on a variety of image sets and retrieves many matches that are subjectively rejected by recent methods. We also demonstrate the usefulness of the framework in structure from motion task for denser point cloud reconstruction.
  • Item
    An Eulerian Approach for Constructing a Map Between Surfaces With Different Topologies
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Park, Hangil; Cho, Youngjin; Bang, Seungbae; Lee, Sung-Hee; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    3D objects of the same kind often have different topologies, and finding correspondence between them is important for operations such as morphing, attribute transfer, and shape matching. This paper presents a novel method to find the surface correspondence between topologically different surfaces. The method is characterized by deforming the source polygonal mesh to match the target mesh by using the intermediate implicit surfaces, and by performing a topological surgery at the appropriate locations on the mesh. In particular, we propose a mathematically well-defined way to detect the topology change of surface by finding the non-degenerate saddle points of the velocity fields that tracks implicit surfaces. We show the effectiveness and possible applications of the proposed method through several experiments.
  • Item
    Retargeting 3D Objects and Scenes with a General Framework
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Huang, Chun-Kai; Chen, Yi-Ling; Shen, I-Chao; Chen, Bing-Yu; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    In this paper, we introduce an interactive method suitable for retargeting both 3D objects and scenes. Initially, the input object or scene is decomposed into a collection of constituent components enclosed by corresponding control bounding volumes which capture the intra-structures of the object or semantic grouping of objects in the 3D scene. The overall retargeting is accomplished through a constrained optimization by manipulating the control bounding volumes. Without inferring the intricate dependencies between the components, we define a minimal set of constraints that maintain the spatial arrangement and connectivity between the components to regularize the valid retargeting results. The default retargeting behavior can then be easily altered by additional semantic constraints imposed by users. This strategy makes the proposed method highly flexible to process a wide variety of 3D objects and scenes under an unified framework. In addition, the proposed method achieved more general structure-preserving pattern synthesis in both object and scene levels. We demonstrate the effectiveness of our method by applying it to several complicated 3D objects and scenes.
  • Item
    Planar Shape Interpolation Based On Teichmüller Mapping
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Nian, Xianshun; Chen, Falai; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Shape interpolation is a classical problem in computer graphics and has been widely investigated in the past two decades. Ideal shape interpolation should be natural and smooth which have good properties such as affine and conformal reproduction, bounded distortion, no fold-overs, etc. In this paper, we present a new approach for planar shape interpolation based on Teichmüller maps - a special type of maps in the class of quasi-conformal maps. The algorithm consists of two steps. In the first step, a Teichmüller map is computed from the source shape to the target shape, and then the Beltrami coefficient is interpolated such that the conformal distortion is linear with respect to the time variable. In the second step, the intermediate shape is reconstructed by solving the Beltrami equation locally over each triangle and then stitching the mapped triangles by conformal transformations. The new approach preserves all the good properties mentioned above and produces more natural and more uniform intermediate shapes than the start-of-the-art methods. Especially, the conformal distortion changes linearly with respect to the time variable. Experiment results show that our method can produce appealing results regardless of interpolating between the same or different objects.
  • Item
    An Efficient Structure-Aware Bilateral Texture Filtering for Image Smoothing
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Lin, Ting-Hao; Way, Der-Lor; Shih, Zen-Chung; Tai, Wen-Kai; Chang, Chin-Chen; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Photos contain well-structured and plentiful visual information. Edges are active and expressive stimuli for human visual perception. However, it is hard to separate structure from details because edge strength and object scale are entirely different concepts. This paper proposes a structure-aware bilateral texture algorithm to remove texture patterns and preserve structures. Our proposed method is simple and fast, as well as effective in removing textures. Instead of patch shift, smaller patches represent pixels located at structure edges, and original patches represent the texture regions. Specifically, this paper also improves joint bilateral filter to preserve small structures. Moreover, a windowed inherent variation is adapted to distinguish textures and structures for detecting structure edges. Finally, the proposed method produces excellent experimental results. These results are compared to some results of previous studies. Besides, structure-preserving filtering is a critical operation in many image processing applications. Our proposed filter is also demonstrated in many attractive applications, such as seam carving, detail enhancement, artistic rendering, etc.
  • Item
    Programmable Animation Texturing using Motion Stamps
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Milliez, Antoine; Guay, Martin; Cani, Marie-Paule; Gross, Markus; Sumner, Robert W.; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Our work on programmable animation texturing enhances the concept of texture mapping by letting artists stylize arbitrary animations using elementary animations, instantiated at the scale of their choice. The core of our workflow resides in two components: we first impose structure and temporal coherence over the animation data using a novel radius-based animationaware clustering. The computed clusters conform to the user-specified scale, and follow the underlying animation regardless of its topology. Extreme mesh deformations, complex particle simulations, or simulated mesh animations with ever-changing topology can therefore be handled in a temporally coherent way. Then, in analogy to fragment shaders that specify an output color based on a texture and a collection of properties defined per vertex (position, texture coordinate, etc.), we provide a programmable interface to the user, letting him or her specify an output animation based on the collection of properties we extract per cluster (position, velocity, etc.). We equip elementary animations with a collection of parameters that are exposed in our programmable system and enables users to script the animated textures depending on properties of the input cluster. We demonstrate the power of our system with complex animated textures created with minimal user input.
  • Item
    Scale-aware Structure-Preserving Texture Filtering
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Jeon, Junho; Lee, Hyunjoon; Kang, Henry; Lee, Seungyong; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    This paper presents a novel method to enhance the performance of structure-preserving image and texture filtering. With conventional edge-aware filters, it is often challenging to handle images of high complexity where features of multiple scales coexist. In particular, it is not always easy to find the right balance between removing unimportant details and protecting important features when they come in multiple sizes, shapes, and contrasts. Unlike previous approaches, we address this issue from the perspective of adaptive kernel scales. Relying on patch-based statistics, our method identifies texture from structure and also finds an optimal per-pixel smoothing scale. We show that the proposed mechanism helps achieve enhanced image/texture filtering performance in terms of protecting the prominent geometric structures in the image, such as edges and corners, and keeping them sharp even after significant smoothing of the original signal.
  • Item
    Real-time Texture Synthesis and Concurrent Random-access Rendering for Low-cost GPU Chip Design
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Zhang, Linling; Fenney, Simon; Escribano, Fernando; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Numerous algorithms have been researched in the area of texture synthesis. However, it remains difficult to design a low-cost synthesis scheme capable of generating high quality results while simultaneously achieving real-time performance. Additional challenges include making a scheme parallel and being able to partially render/synthesize high-resolution textures. Furthermore, it would be beneficial for a synthesis scheme to be able to incorporate Texture Compression and minimize the bandwidth usage, especially on mobile devices. In this paper, we propose a practical method which has low computational complexity and produces textures with small storage requirements. Through use of an index table, random access of the texture is another essential advantage, with which parallel rendering becomes feasible including generation of mip-map sequences. Integrating the index table with existing compression algorithms, for example ETC or PVRTC, the bandwidth is further reduced and avoids the need for a separate, computationally expensive pass to compress the synthesized output. It should be noted that our texture synthesis achieves real-time performance and low power consumption even on mobile devices, for which texture synthesis has been traditionally considered too expensive.
  • Item
    Efficient Volumetric PolyCube-Map Construction
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Fu, Xiao-Ming; Bai, Chong-Yang; Liu, Yang; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    PolyCubes provide compact representations for closed complex shapes and are essential to many computer graphics applications. Existing automatic PolyCube construction methods usually suffer from poor quality or time-consuming computation. In this paper, we provide a highly efficient method to compute volumetric PolyCube-maps. Given an input tetrahedral mesh, we utilize two novel normal-driven volumetric deformation schemes and a polycube-allowable mesh segmentation to drive the input to a volumetric PolyCube structure. Our method can robustly generate foldover-free and low-distortion PolyCube-maps in practice, and provide a flexible control on the number of corners of Polycubes. Compared with state-of-the-art methods, our method is at least one order of magnitude faster and has better mapping qualities. We demonstrate the efficiency and efficacy of our method in PolyCube construction and all-hexahedral meshing on various complex models.
  • Item
    Trip Synopsis: 60km in 60sec
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Huang, Hui; Lischinski, Dani; Hao, Zhuming; Gong, Minglun; Christie, Marc; Cohen-Or, Daniel; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Computerized route planning tools are widely used today by travelers all around the globe, while 3D terrain and urban models are becoming increasingly elaborate and abundant. This makes it feasible to generate a virtual 3D flyby along a planned route. Such a flyby may be useful, either as a preview of the trip, or as an after-the-fact visual summary. However, a naively generated preview is likely to contain many boring portions, while skipping too quickly over areas worthy of attention. In this paper, we introduce 3D trip synopsis: a continuous visual summary of a trip that attempts to maximize the total amount of visual interest seen by the camera. The main challenge is to generate a synopsis of a prescribed short duration, while ensuring a visually smooth camera motion. Using an application-specific visual interest metric, we measure the visual interest at a set of viewpoints along an initial camera path, and maximize the amount of visual interest seen in the synopsis by varying the speed along the route. A new camera path is then computed using optimization to simultaneously satisfy requirements, such as smoothness, focus and distance to the route. The process is repeated until convergence. The main technical contribution of this work is a new camera control method, which iteratively adjusts the camera trajectory and determines all of the camera trajectory parameters, including the camera position, altitude, heading, and tilt. Our results demonstrate the effectiveness of our trip synopses, compared to a number of alternatives.
  • Item
    A Study On Designing Effective Introductory Materials for Information Visualization
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Tanahashi, Yuzuru; Leaf, Nick; Ma, Kwan-Liu; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Designing introductory materials is extremely important when developing new information visualization techniques. All users, regardless of their domain knowledge, first must learn how to interpret the visually encoded information in order to infer knowledge from visualizations. Yet, despite its significance, there has been little research on how to design effective introductory materials for information visualization. This paper presents a study on the design of online guides that educate new users on how to utilize information visualizations, particularly focusing on the employment of exercise questions in the guides. We use two concepts from educational psychology, learning type (or learning style) and teaching method, to design four unique types of online guides. The effects of the guides are measured by comprehension tests of a large group of crowdsourced participants. The tests covered four visualization types (graph, scatter plot, storyline, and tree map) and a complete range of visual analytics tasks. Our statistical analyses indicate that online guides which employ active learning and the top-down teaching method are the most effective. Our study provides quantitative insight into the use of exercise questions in online guides for information visualizations and will inspire further research on design considerations for other elements in introductory materials.
  • Item
    Aesthetic Rating and Color Suggestion for Color Palettes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Kita, Naoki; Miyata, Kazunori; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    A model to rate color combinations that considers human aesthetic preferences is proposed. The proposed method does not assume that a color palette has a specific number of colors, i.e., input is not restricted to a two-, three-, or five-color palettes. We extract features from a color palette whose size does not depend on the number of colors in the palette. The proposed rating prediction model is trained using a human color preference dataset. The model allows a user to extend a color palette, e.g., from three colors to five or seven colors, while retaining color harmony. In addition, we present a color search scheme for a given palette and a customized version of the proposed model for a specific color tone. We demonstrate that the proposed model can also be applied to various palette-based applications.
  • Item
    Temporally Coherent and Artistically Intended Stylization of Feature Lines Extracted from 3D Models
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Cardona, Luis; Saito, Suguru; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    In this paper, we propose a method to maintain the temporal coherence of stylized feature lines extracted from 3D models and preserve an artistically intended stylization provided by the user. We formally define the problem of combining spatio-temporal continuity and artistic intention as a weighted energy minimization problem of competing constraints. The proposed method updates the style properties to provide real-time smooth transitions from current to goal stylization, by assuring first- and second-order temporal continuity, as well as spatial continuity along each stroke. The proposed weighting scheme guarantees that the stylization of strokes maintains motion coherence with respect to the apparent motion of the underlying surface in consecutive frames. This weighting scheme emphasizes temporal continuity for small apparent motions where the human vision system is able to keep track of the scene, and prioritizes the artistic intention for large apparent motions where temporal coherence is not expected. The proposed method produces temporally coherent and visually pleasing animations without the flickering artifacts of previous methods, while also maintaining the artistic intention of a goal stylization provided by the user.
  • Item
    3D Body Shapes Estimation from Dressed-Human Silhouettes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Song, Dan; Tong, Ruofeng; Chang, Jian; Yang, Xiaosong; Tang, Min; Zhang, Jian Jun; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Estimation of 3D body shapes from dressed-human photos is an important but challenging problem in virtual fitting. We propose a novel automatic framework to efficiently estimate 3D body shapes under clothes. We construct a database of 3D naked and dressed body pairs, based on which we learn how to predict 3D positions of body landmarks (which further constrain a parametric human body model) automatically according to dressed-human silhouettes. Critical vertices are selected on 3D registered human bodies as landmarks to represent body shapes, so as to avoid the time-consuming vertices correspondences finding process for parametric body reconstruction. Our method can estimate 3D body shapes from dressed-human silhouettes within 4 seconds, while the fastest method reported previously need 1 minute. In addition, our estimation error is within the size tolerance for clothing industry. We dress 6042 naked bodies with 3 sets of common clothes by physically based cloth simulation technique. To the best of our knowledge, We are the first to construct such a database containing 3D naked and dressed body pairs and our database may contribute to the areas of human body shapes estimation and cloth simulation.
  • Item
    Piecewise Smooth Reconstruction of Normal Vector Field on Digital Data
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Coeurjolly, David; Foare, Marion; Gueth, Pierre; Lachaud, Jacques-Olivier; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a novel method to regularize a normal vector field defined on a digital surface (boundary of a set of voxels). When the digital surface is a digitization of a piecewise smooth manifold, our method localizes sharp features (edges) while regularizing the input normal vector field at the same time. It relies on the optimisation of a variant of the Ambrosio-Tortorelli functional, originally defined for denoising and contour extraction in image processing [AT90]. We reformulate this functional to digital surface processing thanks to discrete calculus operators. Experiments show that the output normal field is very robust to digitization artifacts or noise, and also fairly independent of the sampling resolution. The method allows the user to choose independently the amount of smoothing and the length of the set of discontinuities. Sharp and vanishing features are correctly delineated even on extremely damaged data. Finally, our method can be used to enhance considerably the output of state-ofthe- art normal field estimators like Voronoi Covariance Measure [MOG11] or Randomized Hough Transform [BM12].
  • Item
    Incremental Deformation Subspace Reconstruction
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Mukherjee, Rajaditya; Wu, Xiaofeng; Wang, Huamin; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Recalculating the subspace basis of a deformable body is a mandatory procedure for subspace simulation, after the body gets modified by interactive applications. However, using linear modal analysis to calculate the basis from scratch is known to be computationally expensive. In the paper, we show that the subspace of a modified body can be efficiently obtained from the subspace of its original version, if mesh changes are small. Our basic idea is to approximate the stiffness matrix by its lowfrequency component, so we can calculate new linear deformation modes by solving an incremental eigenvalue decomposition problem. To further handle nonlinear deformations in the subspace, we present a hybrid approach to calculate modal derivatives from both new and original linear modes. Finally, we demonstrate that the cubature samples trained for the original mesh can be reused in fast reduced force and stiffness matrix evaluation, and we explore the use of our techniques in various simulation problems. Our experiment shows that the updated subspace basis still allows a simulator to generate visual plausible deformation effects. The whole system is efficient and it is compatible with other subspace construction approaches.
  • Item
    Piecewise-planar Reconstruction of Multi-room Interiors with Arbitrary Wall Arrangements
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Mura, Claudio; Mattausch, Oliver; Pajarola, Renato; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Reconstructing the as-built architectural shape of building interiors has emerged in recent years as an important and challenging research problem. An effective approach must be able to faithfully capture the architectural structures and separate permanent components from clutter (e.g. furniture), while at the same time dealing with defects in the input data. For many applications, higher-level information on the environment is also required, in particular the shape of individual rooms. To solve this ill-posed problem, state-of-the-art methods assume constrained input environments with a 2.5D or, more restrictively, a Manhattan-world structure, which significantly restricts their applicability in real-world settings. We present a novel pipeline that allows to reconstruct general 3D interior architectures, significantly increasing the range of real-world architectures that can be reconstructed and labeled by any interior reconstruction method to date. Our method finds candidate permanent components by reasoning on a graph-based scene representation, then uses them to build a 3D linear cell complex that is partitioned into separate rooms through a multi-label energy minimization formulation. We demonstrate the effectiveness of our method by applying it to a variety of real-world and synthetic datasets and by comparing it to more specialized state-of-the-art approaches.
  • Item
    Appearance Harmonization for Single Image Shadow Removal
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Ma, Li-Qian; Wang, Jue; Shechtman, Eli; Sunkavalli, Kalyan; Hu, Shi-Min; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Shadow removal is a challenging problem and previous approaches often produce de-shadowed regions that are visually inconsistent with the rest of the image. We propose an automatic shadow region harmonization approach that makes the appearance of a de-shadowed region (produced using any previous technique) compatible with the rest of the image. We use a shadow-guided patch-based image synthesis approach that reconstructs the shadow region using patches sampled from nonshadowed regions. This result is then refined based on the reconstruction confidence to handle unique textures. Qualitative comparisons over a wide range of images, and a quantitative evaluation on a benchmark dataset show that our technique significantly improves upon the state-of-the-art.
  • Item
    Anisotropic Superpixel Generation Based on Mahalanobis Distance
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Cai, Yiqi; Guo, Xiaohu; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Superpixels have been widely used as a preprocessing step in various computer vision tasks. Spatial compactness and color homogeneity are the two key factors determining the quality of the superpixel representation. In this paper, these two objectives are considered separately and anisotropic superpixels are generated to better adapt to local image content. We develop a unimodular Gaussian generative model to guide the color homogeneity within a superpixel by learning local pixel color variations. It turns out maximizing the log-likelihood of our generative model is equivalent to solving a Centroidal Voronoi Tessellation (CVT) problem. Moreover, we provide the theoretical guarantee that the CVT result is invariant to affine illumination change, which makes our anisotropic superpixel generation algorithm well suited for image/video analysis in varying illumination environment. The effectiveness of our method in image/video superpixel generation is demonstrated through the comparison with other state-of-the-art methods.
  • Item
    Image Recoloring with Valence-Arousal Emotion Model
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Kim, Hye-Rin; Kang, Henry; Lee, In-Kwon; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We introduce an affective image recoloring method for changing the overall mood in the image in a numerically measurable way. Given a semantically segmented source image and a target emotion, our system finds reference image segments from the collection of images that have been tagged via crowdsourcing with numerically measured emotion labels. We then recolorize the source segments using colors from the selected target segments while preserving the gradient of the source image to generate a seamless and natural result. User study confirms the effectiveness of our method in accomplishing the stated goal of altering the mood of the image to match the target emotion level.
  • Item
    Non-Local Sparse and Low-Rank Regularization for Structure-Preserving Image Smoothing
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Zhu, Lei; Fu, Chi-Wing; Jin, Yueming; Wei, Mingqiang; Qin, Jing; Heng, Pheng-Ann; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    This paper presents a new image smoothing method that better preserves prominent structures. Our method is inspired by the recent non-local image processing techniques on the patch grouping and filtering. Overall, it has three major contributions over previous works. First, we employ the diffusion map as the guidance image to improve the accuracy of patch similarity estimation using the region covariance descriptor. Second, we model structure-preserving image smoothing as a low-rank matrix recovery problem, aiming at effectively filtering the texture information in similar patches. Lastly, we devise an objective function, namely the weighted robust principle component analysis (WRPCA), by regularizing the low rank with the weighted nuclear norm and sparsity pursuit with L1 norm, and solve this non-convex WRPCA optimization problem by adopting the alternative direction method of multipliers (ADMM) technique. We experiment our method with a wide variety of images and compare it against several state-of-the-art methods. The results show that our method achieves better structure preservation and texture suppression as compared to other methods. We also show the applicability of our method on several image processing tasks such as edge detection, texture enhancement and seam carving.
  • Item
    Skeleton-driven Adaptive Hexahedral Meshing of Tubular Shapes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Livesu, Marco; Muntoni, Alessandro; Puppo, Enrico; Scateni, Riccardo; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a novel method for the automatic generation of structured hexahedral meshes of articulated 3D shapes. We recast the complex problem of generating the connectivity of a hexahedral mesh of a general shape into the simpler problem of generating the connectivity of a tubular structure derived from its curve-skeleton. We also provide volumetric subdivision schemes to nicely adapt the topology of the mesh to the local thickness of tubes, while regularizing per-element size. Our method is fast, one-click, easy to reproduce, and it generates structured meshes that better align to the branching structure of the input shape if compared to previous methods for hexa mesh generation.
  • Item
    Re-Compositable Panoramic Selfie with Robust Multi-Frame Segmentation and Stitching
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Li, Kai; Wang, Jue; Liu, Yebin; Xu, Li; Dai, Qionghai; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    It is a challenging task for ordinary users to capture selfies with a good scene composition, given the limited freedom to position the camera. Creative hardware (e.g., selfie sticks) and software (e.g., panoramic selfie apps) solutions have been proposed to extend the background coverage of a selife, but to achieve a perfect composition on the spot when the selfie is captured remains to be difficult. In this paper, we propose a system that allows the user to shoot a selfie video by rotating the body first, then produce a final panoramic selfie image with user-guided scene composition as postprocessing. Our key technical contribution is a fully automatic, robust multi-frame segmentation and stitching framework that is tailored towards the special characteristics of selfie images. We analyze the sparse feature points and employ a spatial-temporal optimization for bilayer feature segmentation, which leads to more reliable background alignment than previous image stitching techniques. The sparse classification is then propagated to all pixels to create dense foreground masks for person-background composition. Finally, based on a user-selected foreground position, our system uses content-preserving warping to produce a panoramic seflie with minimal distortion to the face region. Experimental results show that our approach can reliably generate high quality panoramic selfies, while a simple combination of previous image stitching and segmentation approaches often fails.
  • Item
    Flow Curves: an Intuitive Interface for Coherent Scene Deformation
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Ciccone, Loïc; Guay, Martin; Sumner, Robert W.; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Effective composition in visual arts relies on the principle of movement, where the viewer's eye is directed along subjective curves to a center of interest. We call these curves subjective because they may span the edges and/or center-lines of multiple objects, as well as contain missing portions which are automatically filled by our visual system. By carefully coordinating the shape of objects in a scene, skilled artists direct the viewer's attention via strong subjective curves. While traditional 2D sketching is a natural fit for this task, current 3D tools are object-centric and do not accommodate coherent deformation of multiple shapes into smooth flows. We address this shortcoming with a new sketch-based interface called Flow Curves which allows coordinating deformation across multiple objects. Core components of our method include an understanding of the principle of flow, algorithms to automatically identify subjective curve elements that may span multiple disconnected objects, and a deformation representation tailored to the view-dependent nature of scene movement. As demonstrated in our video, sketching flow curves requires significantly less time than using traditional 3D editing workflows.
  • Item
    Efficient Modeling of Entangled Details for Natural Scenes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Guérin, Eric; Galin, Eric; Grosbellet, François; Peytavie, Adrien; Génevaux, Jean-David; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Digital landscape realism often comes from the multitude of details that are hard to model such as fallen leaves, rock piles or entangled fallen branches. In this article, we present a method for augmenting natural scenes with a huge amount of details such as grass tufts, stones, leaves or twigs. Our approach takes advantage of the observation that those details can be approximated by replications of a few similar objects and therefore relies on mass-instancing. We propose an original structure, the Ghost Tile, that stores a huge number of overlapping candidate objects in a tile, along with a pre-computed collision graph. Details are created by traversing the scene with the Ghost Tile and generating instances according to user-defined density fields that allow to sculpt layers and piles of entangled objects while providing control over their density and distribution.
  • Item
    Automatic Modeling of Urban Facades from Raw LiDAR Point Data
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Wang, Jun; Xu, Yabin; Remil, Oussama; Xie, Xingyu; Ye, Nan; Wei, Mingqiang; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Modeling of urban facades from raw LiDAR point data remains active due to its challenging nature. In this paper, we propose an automatic yet robust 3D modeling approach for urban facades with raw LiDAR point clouds. The key observation is that building facades often exhibit repetitions and regularities. We hereby formulate repetition detection as an energy optimization problem with a global energy function balancing geometric errors, regularity and complexity of facade structures. As a result, repetitive structures are extracted robustly even in the presence of noise and missing data. By registering repetitive structures, missing regions are completed and thus the associated point data of structures are well consolidated. Subsequently, we detect the potential design intents (i.e., geometric constraints) within structures and perform constrained fitting to obtain the precise structure models. Furthermore, we apply structure alignment optimization to enforce position regularities and employ repetitions to infer missing structures. We demonstrate how the quality of raw LiDAR data can be improved by exploiting data redundancy, and discovering high level structural information (regularity and symmetry). We evaluate our modeling method on a variety of raw LiDAR scans to verify its robustness and effectiveness.
  • Item
    TSS BVHs: Tetrahedron Swept Sphere BVHs for Ray Tracing Subdivision Surfaces
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Du, Peng; Kim, Yong-Jun; Yoon, Sung Eui; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We present a novel, compact bounding volume hierarchy, TSS BVH, for ray tracing subdivision surfaces computed by the Catmull-Clark scheme. We use Tetrahedron Swept Sphere (TSS) as a bounding volume to tightly bound limit surfaces of such subdivision surfaces given a user tolerance. Geometric coordinates defining our TSS bounding volumes are implicitly computed from the subdivided mesh via a simple vertex ordering method, and each level of our TSS BVH is associated with a single distance bound, utilizing the Catmull-Clark scheme. These features result in a linear space complexity as a function of the tree depth, while many prior BVHs have exponential space complexity. We have tested our method against different benchmarks with path tracing and photon mapping. We found that our method achieves up to two orders of magnitude of memory reduction with a high culling ratio over the prior AABB BVH methods, when we represent models with two to four subdivision levels. Overall, our method achieves three times performance improvement thanks to these results. These results are acquired by our theorem that rigorously computes our TSS bounding volumes.
  • Item
    Foveated Real-Time Ray Tracing for Head-Mounted Displays
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Weier, Martin; Roth, Thorsten; Kruijff, Ernst; Hinkenjann, André; Pérard-Gayot, Arsène; Slusallek, Philipp; Li, Yongmin; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Head-mounted displays with dense pixel arrays used for virtual reality applications require high frame rates and low latency rendering. This forms a challenging use case for any rendering approach. In addition to its ability of generating realistic images, ray tracing offers a number of distinct advantages, but has been held back mainly by its performance. In this paper, we present an approach that significantly improves image generation performance of ray tracing. This is done by combining foveated rendering based on eye tracking with reprojection rendering using previous frames in order to drastically reduce the number of new image samples per frame. To reproject samples a coarse geometry is reconstructed from a G-Buffer. Possible errors introduced by this reprojection as well as parts that are critical to the perception are scheduled for resampling. Additionally, a coarse color buffer is used to provide an initial image, refined smoothly by more samples were needed. Evaluations and user tests show that our method achieves real-time frame rates, while visual differences compared to fully rendered images are hardly perceivable. As a result, we can ray trace non-trivial static scenes for the Oculus DK2 HMD at 1182x1464 per eye within the the VSync limits without perceived visual differences.
  • Item
    Minimal Sampling for Effective Acquisition of Anisotropic BRDFs
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Vávra, Radomir; Filip, Jiri; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    BRDFs are commonly used for material appearance representation in applications ranging from gaming and the movie industry, to product design and specification. Most applications rely on isotropic BRDFs due to their better availability as a result of their easier acquisition process. On the other hand, anisotropic BRDF due to their structure-dependent anisotropic highlights, are more challenging to measure and process. This paper thus leverages the measurement process of anisotropic BRDF by representing such BRDF by the collection of isotropic BRDFs. Our method relies on an anisotropic BRDF database decomposition into training isotropic slices forming a linear basis, where appropriate sparse samples are identified using numerical optimization. When an unknown anisotropic BRDF is measured, these samples are repeatably captured in a small set of azimuthal directions. All collected samples are then used for an entire measured BRDF reconstruction from a linear isotropic basis. Typically, below 100 samples are sufficient for the capturing of main visual features of complex anisotropic materials, and we provide a minimal directional samples to be regularly measured at each sample rotation. We conclude, that even simple setups relying on five bidirectional samples (maximum of five stationary sensors/lights) in combination with eight rotations (rotation stage for specimen) can yield a promising reconstruction of anisotropic behavior. Next, we outline extension of the proposed approach to adaptive sampling of anisotropic BRDF to gain even better performance. Finally, we show that our method allows using standard geometries, including industrial multi-angle reflectometers, for the fast measurement of anisotropic BRDFs.
  • Item
    Adaptive Bas-relief Generation from 3D Object under Illumination
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Zhang, Yu-Wei; Zhang, Caiming; Wang, Wenping; Chen, Yanzhao; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Bas-relief is designed to provide 3D perception for the viewers under illumination. For the problem of bas-relief generation from 3D object, most existing methods ignore the influence of illumination on bas-relief appearance. In this paper, we propose a novel method that adaptively generate bas-reliefs with respect to illumination conditions. Given a 3D object and its target appearance, our method finds an adaptive surface that preserves the appearance of the input. We validate our approach through a variety of applications. Experimental results indicate that the proposed approach is effective in producing bas-reliefs with desired appearance under illumination.
  • Item
    An Interactive Design System of Free-Formed Bamboo-Copters
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Nakamura, Morihiro; Koyama, Yuki; Sakamoto, Daisuke; Igarashi, Takeo; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We present an interactive design system for designing free-formed bamboo-copters, where novices can easily design freeformed, even asymmetric bamboo-copters that successfully fly. The designed bamboo-copters can be fabricated using digital fabrication equipment, such as a laser cutter. Our system provides two useful functions for facilitating this design activity. First, it visualizes a simulated flight trajectory of the current bamboo-copter design, which is updated in real time during the user's editing. Second, it provides an optimization function that automatically tweaks the current bamboo-copter design such that the spin quality-how stably it spins-and the flight quality-how high and long it flies-are enhanced. To enable these functions, we present non-trivial extensions over existing techniques for designing free-formed model airplanes [UKSI14], including a wing discretization method tailored to free-formed bamboo-copters and an optimization scheme for achieving stable bamboocopters considering both spin and flight qualities.
  • Item
    Direct Shape Optimization for Strengthening 3D Printable Objects
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Zhou, Yahan; Kalogerakis, Evangelos; Wang, Rui; Grosse, Ian R.; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Recently there has been an increasing demand for software that can help designers create functional 3D objects with required physical strength. We introduce a generic and extensible method that directly optimizes a shape subject to physical and geometric constraints. Given an input shape, our method optimizes directly its input mesh representation until it can withstand specified external forces, while remaining similar to the original shape. Our method performs physics simulation and shape optimization together in a unified framework, where the physics simulator is an integral part of the optimizer. We employ geometric constraints to preserve surface details and shape symmetry, and adapt a second-order method with analytic gradients to improve convergence and computation time. Our method provides several advantages over previous work, including the ability to handle general shape deformations, preservation of surface details, and incorporation of user-defined constraints. We demonstrate the effectiveness of our method on a variety of printable 3D objects through detailed simulations as well as physical validations.
  • Item
    Anaglyph Caustics with Motion Parallax
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Lancelle, Marcel; Martin, Tobias; Solenthaler, Barbara; Gross, Markus; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    In this paper we present a method to model and simulate a lens such that its caustic reveals a stereoscopic 3D image when viewed through anaglyph glasses. By interpreting lens dispersion as stereoscopic disparity, our method optimizes the shape and arrangement of prisms constituting the lens, such that the resulting anaglyph caustic corresponds to a given input image defined by intensities and disparities. In addition, a slight change of the lens' distance to the screen causes a 3D parallax effect that can also be perceived without glasses. Our proposed relaxation method carefully balances the resulting pixel intensity and disparity error, while taking the subsequent physical fabrication process into account. We demonstrate our method on a representative set of input images and evaluate the anaglyph caustics using multi-spectral photon tracing. We further show the fabrication of prototype lenses with a laser cutter as a proof of concept.
  • Item
    Proxy-guided Image-based Rendering for Mobile Devices
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Reinert, Bernhard; Kopf, Johannes; Ritschel, Tobias; Cuervo, Eduardo; Chu, David; Seidel, Hans-Peter; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    VR headsets and hand-held devices are not powerful enough to render complex scenes in real-time. A server can take on the rendering task, but network latency prohibits a good user experience. We present a new image-based rendering (IBR) architecture for masking the latency. It runs in real-time even on very weak mobile devices, supports modern game engine graphics, and maintains high visual quality even for large view displacements. We propose a novel server-side dual-view representation that leverages an optimally-placed extra view and depth peeling to provide the client with coverage for filling disocclusion holes. This representation is directly rendered in a novel wide-angle projection with favorable directional parameterization. A new client-side IBR algorithm uses a pre-transmitted level-of-detail proxy with an encaging simplification and depth-carving to maintain highly complex geometric detail. We demonstrate our approach with typical VR / mobile gaming applications running on mobile hardware. Our technique compares favorably to competing approaches according to perceptual and numerical comparisons.
  • Item
    Pixel History Linear Models for Real-Time Temporal Filtering
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Iglesias-Guitian, Jose A.; Moon, Bochang; Koniaris, Charalampos; Smolikowski, Eric; Mitchell, Kenny; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a new real-time temporal filtering and antialiasing (AA) method for rasterization graphics pipelines. Our method is based on Pixel History Linear Models (PHLM), a new concept for modeling the history of pixel shading values over time using linear models. Based on PHLM, our method can predict per-pixel variations of the shading function between consecutive frames. This combines temporal reprojection with per-pixel shading predictions in order to provide temporally coherent shading, even in the presence of very noisy input images. Our method can address both spatial and temporal aliasing problems under a unique filtering framework that minimizes filtering error through a recursive least squares algorithm. We demonstrate our method working with a commercial deferred shading engine for rasterization and with our own OpenGL deferred shading renderer.We have implemented our method in GPU and it has shown significant reduction of temporal flicker in very challenging scenarios including foliage rendering, complex non-linear camera motions, dynamic lighting, reflections, shadows and fine geometric details. Our approach, based on PHLM, avoids the creation of visible ghosting artifacts and it reduces the filtering overblur characteristic of temporal deflickering methods. At the same time, the results are comparable to state-of-the-art realtime filters in terms of temporal coherence.
  • Item
    Multiple Scattering Approximation in Heterogeneous Media by Narrow Beam Distributions
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Shinya, Mikio; Dobashi, Yoshinori; Shiraishi, Michio; Kawashima, Motonobu; Nishita, Tomoyuki; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Fast realistic rendering of objects in scattering media is still a challenging topic in computer graphics. In presence of participating media, a light beam is repeatedly scattered by media particles, changing direction and getting spread out. Explicitly evaluating this beam distribution would enable efficient simulation of multiple scattering events without involving costly stochastic methods. Narrow beam theory provides explicit equations that approximate light propagation in a narrow incident beam. Based on this theory, we propose a closed-form distribution function for scattered beams. We successfully apply it to the image synthesis of scenes in which scattering occurs, and show that our proposed estimation method is more accurate than those based on the Wentzel-Kramers-Brillouin (WKB) theory.
  • Item
    Merged Multiresolution Hierarchies for Shadow Map Compression
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Scandolo, Leonardo; Bauszat, Pablo; Eisemann, Elmar; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Multiresolution Hierarchies (MH) and Directed Acyclic Graphs (DAG) are two recent approaches for the compression of highresolution shadow information. In this paper, we introduce Merged Multiresolution Hierarchies (MMH), a novel data structure that unifies both concepts. An MMH leverages both hierarchical homogeneity exploited in MHs, as well as topological similarities exploited in DAG representations. We propose an efficient hash-based technique to quickly identify and remove redundant subtree instances in a modified relative MH representation. Our solution remains lossless and significantly improves the compression rate compared to both preceding shadow map compression algorithms, while retaining the full run-time performance of traditional MH representations.
  • Item
    Facial Feature Exaggeration According to Social Psychology of Face Perception
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Tian, Lihui; Xiao, Shuangjiu; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a personality trait exaggeration system emphasizing the impression of human face in images, based on multi-level features learning and exaggeration. These features are called Personality Trait Model(PTM). Abstract level of PTM is social psychology trait of face perception such as amiable, mean, cute and so on. Concrete level of PTM is shape feature and texture feature. A training phase is presented to learn multi-level features of faces from different images. Statistical survey is taken to label sample images with people's first impressions. From images with the same labels, we capture not only shape features but also texture features to enhance exaggeration effect. Texture feature is expressed by matrix to reflect depth of facial organs, wrinkles and so on. In application phase, original images will be exaggerated using PTM iteratively. And exaggeration rate for each iteration is constrained to keep likeness with the original face. Experimental results demonstrate that our system can emphasize chosen social psychology traits effectively.
  • Item
    Efficient Multi-image Correspondences for On-line Light Field Video Processing
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Dąbała, Łukasz; Ziegler, Matthias; Didyk, Piotr; Zilly, Frederik; Keinert, Joachim; Myszkowski, Karol; Seidel, Hans-Peter; Rokita, Przemysław; Ritschel, Tobias; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Light field videos express the entire visual information of an animated scene, but their shear size typically makes capture, processing and display an off-line process, i. e., time between initial capture and final display is far from real-time. In this paper we propose a solution for one of the key bottlenecks in such a processing pipeline, which is a reliable depth reconstruction possibly for many views. This is enabled by a novel correspondence algorithm converting the video streams from a sparse array of off-the-shelf cameras into an array of animated depth maps. The algorithm is based on a generalization of the classic multi-resolution Lucas-Kanade correspondence algorithm from a pair of images to an entire array. Special inter-image confidence consolidation allows recovery from unreliable matching in some locations and some views. It can be implemented efficiently in massively parallel hardware, allowing for interactive computations. The resulting depth quality as well as the computation performance compares favorably to other state-of-the art light field-to-depth approaches, as well as stereo matching techniques. Another outcome of this work is a data set of light field videos that are captured with multiple variants of sparse camera arrays.
  • Item
    Physically Based Video Editing
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Bazin, Jean-Charles; Plüss (Kuster), Claudia; Yu, Guo; Martin, Tobias; Jacobson, Alec; Gross, Markus; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Convincing manipulation of objects in live action videos is a difficult and often tedious task. Skilled video editors achieve this with the help of modern professional tools, but complex motions might still lack physical realism since existing tools do not consider the laws of physics. On the other hand, physically based simulation promises a high degree of realism, but typically creates a virtual 3D scene animation rather than returning an edited version of an input live action video. We propose a framework that combines video editing and physics-based simulation. Our tool assists unskilled users in editing an input image or video while respecting the laws of physics and also leveraging the image content. We first fit a physically based simulation that approximates the object's motion in the input video. We then allow the user to edit the physical parameters of the object, generating a new physical behavior for it. The core of our work is the formulation of an image-aware constraint within physics simulations. This constraint manifests as external control forces to guide the object in a way that encourages proper texturing at every frame, yet producing physically plausible motions. We demonstrate the generality of our method on a variety of physical interactions: rigid motion, multi-body collisions, clothes and elastic bodies.
  • Item
    Feature-Aware Pixel Art Animation
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Kuo, Ming-Hsun; Yang, Yong-Liang; Chu, Hung-Kuo; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Pixel art is a modern digital art in which high resolution images are abstracted into low resolution pixelated outputs using concise outlines and reduced color palettes. Creating pixel art is a labor intensive and skill-demanding process due to the challenge of using limited pixels to represent complicated shapes. Not surprisingly, generating pixel art animation is even harder given the additional constraints imposed in the temporal domain. Although many powerful editors have been designed to facilitate the creation of still pixel art images, the extension to pixel art animation remains an unexplored direction. Existing systems typically request users to craft individual pixels frame by frame, which is a tedious and error-prone process. In this work, we present a novel animation framework tailored to pixel art images. Our system bases on conventional key-frame animation framework and state-of-the-art image warping techniques to generate an initial animation sequence. The system then jointly optimizes the prominent feature lines of individual frames respecting three metrics that capture the quality of the animation sequence in both spatial and temporal domains. We demonstrate our system by generating visually pleasing animations on a variety of pixel art images, which would otherwise be difficult by applying state-of-the-art techniques due to severe artifacts.
  • Item
    An Error Estimation Framework for Many-Light Rendering
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Nabata, Kosuke; Iwasaki, Kei; Dobashi, Yoshinori; Nishita, Tomoyuki; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    The popularity of many-light rendering, which converts complex global illumination computations into a simple sum of the illumination from virtual point lights (VPLs), for predictive rendering has increased in recent years. A huge number of VPLs are usually required for predictive rendering at the cost of extensive computational time. While previous methods can achieve significant speedup by clustering VPLs, none of these previous methods can estimate the total errors due to clustering. This drawback imposes on users tedious trial and error processes to obtain rendered images with reliable accuracy. In this paper, we propose an error estimation framework for many-light rendering. Our method transforms VPL clustering into stratified sampling combined with confidence intervals, which enables the user to estimate the error due to clustering without the costly computing required to sum the illumination from all the VPLs. Our estimation framework is capable of handling arbitrary BRDFs and is accelerated by using visibility caching, both of which make our method more practical. The experimental results demonstrate that our method can estimate the error much more accurately than the previous clustering method.
  • Item
    Decoupled Space and Time Sampling of Motion and Defocus Blur for Unified Rendering of Transparent and Opaque Objects
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Widmer, Sven; Wodniok, Dominik; Thul, Daniel; Guthe, Stefan; Goesele, Michael; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a unified rendering approach that jointly handles motion and defocus blur for transparent and opaque objects at interactive frame rates. Our key idea is to create a sampled representation of all parts of the scene geometry that are potentially visible at any point in time for the duration of a frame in an initial rasterization step. We store the resulting temporally-varying fragments (t-fragments) in a bounding volume hierarchy which is rebuild every frame using a fast spatial median construction algorithm. This makes our approach suitable for interactive applications with dynamic scenes and animations. Next, we perform spatial sampling to determine all t-fragments that intersect with a specific viewing ray at any point in time. Viewing rays are sampled according to the lens uv-sampling for depth-of-field effects. In a final temporal sampling step, we evaluate the predetermined viewing ray/t-fragment intersections for one or multiple points in time. This allows us to incorporate all standard shading effects including transparency. We describe the overall framework, present our GPU implementation, and evaluate our rendering approach with respect to scalability, quality, and performance.
  • Item
    Variance Analysis of Multi-sample and One-sample Multiple Importance Sampling
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Sbert, Mateu; Havran, Vlastimil; Szirmay-Kalos, Laszlo; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We reexamine in this paper the variance for the Multiple Importance Sampling (MIS) estimator for multi-sample and onesample model. As a result of our analysis we can obtain the optimal estimator for the multi-sample model for the case where the weights do not depend on the count of samples. We extend the analysis to include the cost of sampling. With these results in hand we find a better estimator than balance heuristic with equal count of samples. Further, we show that the variance for the one-sample model is larger or equal than for the multi-sample model, and that there are only two cases where the variance is the same. Finally, we study on four examples the difference of variances for equal count as used by Veach, our new estimator, and a recently introduced heuristic.
  • Item
    Reduced Aggregate Scattering Operators for Path Tracing
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Blumer, Adrian; Novák, Jan; Habel, Ralf; Nowrouzezahrai, Derek; Jarosz, Wojciech; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Aggregate scattering operators (ASOs) describe the overall scattering behavior of an asset (i.e., an object or volume, or collection thereof) accounting for all orders of its internal scattering. We propose a practical way to precompute and compactly store ASOs and demonstrate their ability to accelerate path tracing. Our approach is modular avoiding costly and inflexible scene-dependent precomputation. This is achieved by decoupling light transport within and outside of each asset, and precomputing on a per-asset level. We store the internal transport in a reduced-dimensional subspace tailored to the structure of the asset geometry, its scattering behavior, and typical illumination conditions, allowing the ASOs to maintain good accuracy with modest memory requirements. The precomputed ASO can be reused across all instances of the asset and across multiple scenes. We augment ASOs with functionality enabling multi-bounce importance sampling, fast short-circuiting of complex light paths, and compact caching, while retaining rapid progressive preview rendering. We demonstrate the benefits of our ASOs by efficiently path tracing scenes containing many instances of objects with complex inter-reflections or multiple scattering.
  • Item
    Progressive Compression of Arbitrary Textured Meshes
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Caillaud, Florian; Vidal, Vincent; Dupont, Florent; Lavoué, Guillaume; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    In this paper, we present a progressive compression algorithm for textured surface meshes, which is able to handle polygonal non-manifold meshes as well as discontinuities in the texture mapping. Our method applies iterative batched simplifications, which create high quality levels of detail by preserving both the geometry and the texture mapping. The main features of our algorithm are (1) generic edge collapse and vertex split operators suited for polygonal non-manifold meshes with arbitrary texture seam configurations, and (2) novel geometry-driven prediction schemes and entropy reduction techniques for efficient encoding of connectivity and texture mapping. To our knowledge, our method is the first progressive algorithm to handle polygonal non-manifold models. For geometry and connectivity encoding of triangular manifolds and non-manifolds, our method is competitive with state-of-the-art and even better at low/medium bitrates. Moreover, our method allows progressive encoding of texture coordinates with texture seams; it outperforms state-of-the-art approaches for texture coordinate encoding. We also present a bit-allocation framework which multiplexes mesh and texture refinement data using a perceptually-based image metric, in order to optimize the quality of levels of detail.
  • Item
    Tracing Field-Coherent Quad Layouts
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Pietroni, Nico; Puppo, Enrico; Marcias, Giorgio; Scopigno, Roberto; Cignoni, Paolo; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Given a cross field over a triangulated surface we present a practical and robust method to compute a field aligned coarse quad layout over the surface. The method works directly on a triangle mesh without requiring any parametrization and it is based on a new technique for tracing field-coherent geodesic paths directly on a triangle mesh, and on a new relaxed formulation of a binary LP problem, which allows us to extract both conforming quad layouts and coarser layouts containing t-junctions. Our method is easy to implement, very robust, and, being directly based on the input cross field, it is able to generate better aligned layouts, even with complicated fields containing many singularities. We show results on a number of datasets and comparisons with state-of-the-art methods.
  • Item
    Visual Contrast Sensitivity and Discrimination for 3D Meshes and their Applications
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Nader, Georges; Wang, Kai; Hétroy-Wheeler, Franck; Dupont, Florent; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    In this paper, we first introduce an algorithm for estimating the visual contrast on a 3D mesh. We then perform a series of psychophysical experiments to study the effects of contrast sensitivity and contrast discrimination of the human visual system for the task of differentiating between two contrasts on a 3D mesh. The results of these experiments allow us to propose a perceptual model that is able to predict whether a change in local contrast on 3D mesh, induced by a local geometric distortion, is visible or not. Finally, we illustrate the utility of the proposed perceptual model in a number of applications: we compute the Just Noticeable Distortion (JND) profile for smooth-shaded 3D meshes and use the model to guide mesh processing algorithms.
  • Item
    Harmonic Functions for Rotational Symmetry Vector Fields
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Shen, Zhongwei; Fang, Xianzhong; Liu, Xinguo; Bao, Hujun; Huang, Jin; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    Representing rotational symmetry vector as a set of vectors is not suitable for design due to lacking of a consistent ordering for measurement. In this paper we introduce a spectral method to find rotation invariant harmonic functions for symmetry vector field design. This method is developed for 3D vector fields, but it is applicable in 2D. Given the finite symmetry group G of a symmetry vector field v(x) on a 3D domain W, we formulate the harmonic function h(s) as a stationary point of group G. Using the real spherical harmonic (SH) bases, we showed the coefficients of the harmonic functions are an eigenvector of the SH rotation matrices corresponding to group G. Instead of solving eigen problems to obtain the eigenvector, we developed a forward constructive method based on orthogonal group theory. The harmonic function found by our method is not only invariant under G, but also expressive and can distinguish different rotations with respect to G. At last, we demonstrate some vector field design results with tetrahedron-symmetry, cube-symmetry and dodecahedron-symmetry groups.
  • Item
    A Multilevel SPH Solver with Unified Solid Boundary Handling
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Takahashi, Tetsuya; Lin, Ming C.; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We propose a geometric multilevel solver for efficiently solving linear systems arising from particle-based methods. To apply this method to particle systems, we construct the hierarchy, establish the correspondence between solutions at the particle and grid levels, and coarsen simulation elements taking boundary conditions into account. In addition, we propose a new solid boundary handling method to solve a pressure Poisson equation in a unified manner. We demonstrate that our method can handle general fluid simulation scenarios including two-way fluid-solid coupling, and the computational cost of this new solver scales nearly linearly with respect to the number of unknowns, unlike previous solvers for particle-based methods.