End-to-End View Synthesis for Light Field Imaging with Pseudo 4DCNN

Limited angular resolution has become the main bottleneck of microlens-based plenoptic cameras towards practical vision applications. Existing view synthesis methods mainly break the task into two steps, i.e. depth estimating and view warping, which are usually inefficient and produce artifacts over depth ambiguities. In this paper, an end-to-end deep learning framework is proposed to solve these problems by exploring Pseudo 4DCNN. Specifically, 2D strided convolutions operated on stacked EPIs and detail-restoration 3D CNNs connected with angular conversion are assembled to build the Pseudo 4DCNN. The key advantage is to efficiently synthesize dense 4D light fields from a sparse set of input views. The learning framework is well formulated as an entirely trainable problem, and all the weights can be recursively updated with standard backpropagation. The proposed framework is compared with state-of-the-art approaches on both genuine and synthetic light field databases, which achieves significant improvements of both image quality (+2 dB higher) and computational efficiency (over 10X faster). Furthermore, the proposed framework shows good performances in real-world applications such as biometrics and depth estimation.

[1]  Gordon Wetzstein,et al.  The light field stereoscope , 2015, ACM Trans. Graph..

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

[3]  P. Hanrahan,et al.  Light Field Photography with a Hand-held Plenoptic Camera , 2005 .

[4]  Alexei A. Efros,et al.  Occlusion-Aware Depth Estimation Using Light-Field Cameras , 2015, 2015 IEEE International Conference on Computer Vision (ICCV).

[5]  Frédo Durand,et al.  Linear view synthesis using a dimensionality gap light field prior , 2010, 2010 IEEE Computer Society Conference on Computer Vision and Pattern Recognition.

[6]  Bastian Goldlücke,et al.  A Dataset and Evaluation Methodology for Depth Estimation on 4D Light Fields , 2016, ACCV.

[7]  Jian Sun,et al.  Deep Residual Learning for Image Recognition , 2015, 2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[8]  Shi-Min Hu,et al.  PlenoPatch: Patch-Based Plenoptic Image Manipulation , 2017, IEEE Transactions on Visualization and Computer Graphics.

[9]  Anita Sellent,et al.  Floating Textures , 2008, Comput. Graph. Forum.

[10]  Lorenzo Torresani,et al.  Learning Spatiotemporal Features with 3D Convolutional Networks , 2014, 2015 IEEE International Conference on Computer Vision (ICCV).

[11]  Ravi Ramamoorthi,et al.  Learning to Synthesize a 4D RGBD Light Field from a Single Image , 2017, 2017 IEEE International Conference on Computer Vision (ICCV).

[12]  Qionghai Dai,et al.  Light Field Image Processing: An Overview , 2017, IEEE Journal of Selected Topics in Signal Processing.

[13]  John Salvatier,et al.  Theano: A Python framework for fast computation of mathematical expressions , 2016, ArXiv.

[14]  In-So Kweon,et al.  Light-Field Image Super-Resolution Using Convolutional Neural Network , 2017, IEEE Signal Processing Letters.

[15]  Stefan B. Williams,et al.  Decoding, Calibration and Rectification for Lenselet-Based Plenoptic Cameras , 2013, 2013 IEEE Conference on Computer Vision and Pattern Recognition.

[16]  Tieniu Tan,et al.  High quality depth map estimation of object surface from light-field images , 2017, Neurocomputing.

[17]  George Drettakis,et al.  Depth synthesis and local warps for plausible image-based navigation , 2013, TOGS.

[18]  In-So Kweon,et al.  Learning a Deep Convolutional Network for Light-Field Image Super-Resolution , 2015, 2015 IEEE International Conference on Computer Vision Workshop (ICCVW).

[19]  M. Landy,et al.  The Plenoptic Function and the Elements of Early Vision , 1991 .

[20]  Qionghai Dai,et al.  Light Field Reconstruction Using Deep Convolutional Network on EPI , 2017, 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[21]  Frédo Durand,et al.  Light Field Reconstruction Using Sparsity in the Continuous Fourier Domain , 2014, ACM Trans. Graph..

[22]  Sven Wanner,et al.  Variational Light Field Analysis for Disparity Estimation and Super-Resolution , 2014, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[23]  Qionghai Dai,et al.  Light field from micro-baseline image pair , 2015, 2015 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[24]  Leonidas J. Guibas,et al.  Volumetric and Multi-view CNNs for Object Classification on 3D Data , 2016, 2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[25]  Alexei A. Efros,et al.  Depth Estimation with Occlusion Modeling Using Light-Field Cameras , 2016, IEEE Transactions on Pattern Analysis and Machine Intelligence.

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