Convolutional Neural Opacity Radiance Fields

Photo-realistic modeling and rendering of fuzzy objects with complex opacity are critical for numerous immersive VR/AR applications, but it suffers from strong view-dependent brightness, color. In this paper, we propose a novel scheme to generate opacity radiance fields with a convolutional neural renderer for fuzzy objects, which is the first to combine both explicit opacity supervision and convolutional mechanism into the neural radiance field framework so as to enable high-quality appearance and global consistent alpha mattes generation in arbitrary novel views. More specifically, we propose an efficient sampling strategy along with both the camera rays and image plane, which enables efficient radiance field sampling and learning in a patch-wise manner, as well as a novel volumetric feature integration scheme that generates per-patch hybrid feature embeddings to reconstruct the view-consistent fine-detailed appearance and opacity output. We further adopt a patch-wise adversarial training scheme to preserve both high-frequency appearance and opacity details in a self-supervised framework. We also introduce an effective multi-view image capture system to capture high-quality color and alpha maps for challenging fuzzy objects. Extensive experiments on existing and our new challenging fuzzy object dataset demonstrate that our method achieves photo-realistic, globally consistent, and fined detailed appearance and opacity free-viewpoint rendering for various fuzzy objects.

[1]  Kiriakos N. Kutulakos,et al.  A Neural Rendering Framework for Free-Viewpoint Relighting , 2020, 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[2]  Li Fei-Fei,et al.  Perceptual Losses for Real-Time Style Transfer and Super-Resolution , 2016, ECCV.

[3]  Andreas Geiger,et al.  Differentiable Volumetric Rendering: Learning Implicit 3D Representations Without 3D Supervision , 2020, 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[4]  Kai Zhang,et al.  NeRF++: Analyzing and Improving Neural Radiance Fields , 2020, ArXiv.

[5]  Michael Bosse,et al.  Unstructured lumigraph rendering , 2001, SIGGRAPH.

[6]  Marco Forte,et al.  F, B, Alpha Matting , 2020, ArXiv.

[7]  S. Shankar Sastry,et al.  Dissimilarity-Based Sparse Subset Selection , 2014, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[8]  Yue Qi,et al.  Dynamic hair capture using spacetime optimization , 2014, ACM Trans. Graph..

[9]  Ziyu Wang,et al.  Neural Opacity Point Cloud , 2020, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[10]  Dani Lischinski,et al.  A Closed-Form Solution to Natural Image Matting , 2006, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[11]  Min H. Kim,et al.  Strand-accurate Multiview Hair Capture , 2022 .

[12]  Feng Liu,et al.  Context-Aware Image Matting for Simultaneous Foreground and Alpha Estimation , 2019, 2019 IEEE/CVF International Conference on Computer Vision (ICCV).

[13]  Gordon Wetzstein,et al.  Scene Representation Networks: Continuous 3D-Structure-Aware Neural Scene Representations , 2019, NeurIPS.

[14]  Kyaw Zaw Lin,et al.  Neural Sparse Voxel Fields , 2020, NeurIPS.

[15]  Sebastian Nowozin,et al.  Occupancy Networks: Learning 3D Reconstruction in Function Space , 2018, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[16]  Jonathan T. Barron,et al.  NeRF in the Wild: Neural Radiance Fields for Unconstrained Photo Collections , 2020, 2021 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[17]  Pratul P. Srinivasan,et al.  NeRF , 2020, ECCV.

[18]  Marc Levoy,et al.  Light field rendering , 1996, SIGGRAPH.

[19]  Jonathan T. Barron,et al.  Fourier Features Let Networks Learn High Frequency Functions in Low Dimensional Domains , 2020, NeurIPS.

[20]  Deepu Rajan,et al.  Improving Image Matting Using Comprehensive Sampling Sets , 2013, 2013 IEEE Conference on Computer Vision and Pattern Recognition.

[21]  Alexei A. Efros,et al.  The Unreasonable Effectiveness of Deep Features as a Perceptual Metric , 2018, 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition.

[22]  Ning Xu,et al.  Deep Image Matting , 2017, 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[23]  Frédo Durand,et al.  Hair photobooth: geometric and photometric acquisition of real hairstyles , 2008, ACM Trans. Graph..

[24]  Ira Kemelmacher-Shlizerman,et al.  Background Matting: The World Is Your Green Screen , 2020, 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[25]  Jiangyu Liu,et al.  Disentangled Image Matting , 2019, 2019 IEEE/CVF International Conference on Computer Vision (ICCV).

[26]  Jian Sun,et al.  Poisson matting , 2004, ACM Trans. Graph..

[27]  Leonidas J. Guibas,et al.  ShapeNet: An Information-Rich 3D Model Repository , 2015, ArXiv.

[28]  David Salesin,et al.  A Bayesian approach to digital matting , 2001, Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001.

[29]  Manuel Menezes de Oliveira Neto,et al.  Shared Sampling for Real‐Time Alpha Matting , 2010, Comput. Graph. Forum.

[30]  Hao Zhang,et al.  Learning Implicit Fields for Generative Shape Modeling , 2018, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[31]  Gordon Wetzstein,et al.  DeepVoxels: Learning Persistent 3D Feature Embeddings , 2018, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[32]  Thomas S. Huang,et al.  Free-Form Image Inpainting With Gated Convolution , 2018, 2019 IEEE/CVF International Conference on Computer Vision (ICCV).

[33]  Alexei A. Efros,et al.  Image-to-Image Translation with Conditional Adversarial Networks , 2016, 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[34]  Takeo Kanade,et al.  Shape-from-silhouette of articulated objects and its use for human body kinematics estimation and motion capture , 2003, 2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2003. Proceedings..

[35]  Rüdiger Westermann,et al.  RANDOM WALKS FOR INTERACTIVE ALPHA-MATTING , 2005 .

[36]  Richard Szeliski,et al.  Image-Based Modeling and Rendering , 2020 .

[37]  Paul A. Beardsley,et al.  Image-based 3D photography using opacity hulls , 2002, ACM Trans. Graph..

[38]  Szymon Rusinkiewicz,et al.  Structure-aware hair capture , 2013, ACM Trans. Graph..

[39]  Qiang Hu,et al.  Multi-View Neural Human Rendering , 2020, 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[40]  Richard A. Newcombe,et al.  DeepSDF: Learning Continuous Signed Distance Functions for Shape Representation , 2019, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[41]  Victor Lempitsky,et al.  Neural Point-Based Graphics , 2019, ECCV.

[42]  Justus Thies,et al.  Deferred Neural Rendering: Image Synthesis using Neural Textures , 2019 .

[43]  Zhengyou Zhang,et al.  Flexible camera calibration by viewing a plane from unknown orientations , 1999, Proceedings of the Seventh IEEE International Conference on Computer Vision.

[44]  Frédo Durand,et al.  Hair photobooth , 2008, SIGGRAPH 2008.

[45]  Chi-Keung Tang,et al.  KNN Matting , 2012, 2012 IEEE Conference on Computer Vision and Pattern Recognition.

[46]  Ting-Chun Wang,et al.  Learning-based view synthesis for light field cameras , 2016, ACM Trans. Graph..

[47]  Hujun Bao,et al.  A Late Fusion CNN for Digital Matting , 2019, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR).

[48]  Shenghua Gao,et al.  Deep Surface Light Fields , 2018, PACMCGIT.

[49]  Marc Pollefeys,et al.  Convolutional Occupancy Networks , 2020, ECCV.

[50]  Jonathan T. Barron,et al.  Deformable Neural Radiance Fields , 2020, ArXiv.

[51]  Qinping Zhao,et al.  Image Matting with Local and Nonlocal Smooth Priors , 2013, 2013 IEEE Conference on Computer Vision and Pattern Recognition.

[52]  Michael F. Cohen,et al.  An iterative optimization approach for unified image segmentation and matting , 2005, Tenth IEEE International Conference on Computer Vision (ICCV'05) Volume 1.

[53]  Tatsuya Harada,et al.  Neural 3D Mesh Renderer , 2017, 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition.

[54]  Aykut Erdem,et al.  Image Matting with KL-Divergence Based Sparse Sampling , 2015, 2015 IEEE International Conference on Computer Vision (ICCV).

[55]  Hao Li,et al.  PIFu: Pixel-Aligned Implicit Function for High-Resolution Clothed Human Digitization , 2019, 2019 IEEE/CVF International Conference on Computer Vision (ICCV).

[56]  Ning Xu,et al.  High-Resolution Deep Image Matting , 2020, AAAI.