Fast Implicit Neural Light Field Representation via Geometric Decomposition and Multi-Resolution Low-Rank Features
Authors: Yao Guo, Ligen Shi, Shuchen Sun, Jun Qiu, Chang Liu
Organizations: Institute of Computational Imaging, Beijing Information Science and Technology University, Beijing 102206, China · College of Computer Science (College of Software), Inner Mongolia University, Hohhot 010021, China
Implicit neural representations provide a compact and continuous way to reconstruct dense light fields from sampled ray coordinates. However, fast light field reconstruction remains challenging because a light field is a high-dimensional signal with strong spatial-angular redundancy and structured disparity variations. Directly fitting 4D ray coordinates with a neural network often requires considerable optimization time to recover both view appearance and cross-view consistency. To address this issue, this paper proposes a fast implicit light field representation based on geometric decomposition and multi-resolution low-rank features. The proposed method decomposes a 4D light field into a horizontal disparity plane, a spatial texture plane, and a vertical disparity plane. Each plane is represented by a low-rank structure that combines a low-resolution 2D grid with the element-wise product of two high-resolution 1D line features at multiple resolution levels. The fused features are decoded by a lightweight multilayer perceptron to predict RGB values. Experiments on public light field datasets show that the proposed method achieves competitive reconstruction quality while providing a better trade-off among model parameters, training time, and inference efficiency.
Figures & tables
Fig. 1: Overview of the proposed framework. A queried ray r=(u,v,x,y) is mapped onto three feature planes. Each plane uses a multi-resolution low-rank representation that combines a low-resolution 2D grid Gabℓ with the element-wise product of two high-resolution 1D line features Laℓ and Lbℓ . The concatenated features are decoded by a lightweight MLP to predict the ray color.
Dataset
Method
PSNR (dB) ↑
SSIM ↑
LPIPS ↓
EPFL
SIGNET
33.96 ± 2.67
0.93 ± 0.04
0.09 ± 0.05
RSEN
30.10 ± 1.64
0.87 ± 0.05
0.19 ± 0.06
RDF
31.85 ± 1.73
0.94 ± 0.02
0.07 ± 0.05
Ours
35.45 ± 2.55
0.93 ± 0.03
0.02 ± 0.02
INRIA
SIGNET
35.43 ± 3.07
0.91 ± 0.06
0.12 ± 0.05
RSEN
30.99 ± 1.81
0.85 ± 0.09
0.24 ± 0.07
TABLE I: Quantitative comparison on public LF datasets. Best results are marked in bold. The average is computed over datasets.
Fig. 2: Qualitative visual comparison of different methods on representative images selected from the EPFL, INRIA Lytro, and Stanford Gantry datasets, including the challenging Tarot scene. The results are shown for the center views, including reconstructed images and corresponding error maps.
Method
Params. (M)
Train. (min)
Infer. (s)
SIGNET
2.37
360
20
RSEN
1.40
180
9
RDF
0.66
72
12
Ours
1.55
21
8
TABLE II: Efficiency comparison of different methods on the INRIA Lytro dataset.
Scene
Target PSNR (dB)
Train.(min)
SIGNET
RSEN
RDF
Ours
Bee
25.33
11
29
75
0.8
Building
29.93
37
168
70
2.0
Hublai
29.17
45
155
73
1.5
MessyDesk
33.44
72
173
62
2.0
Sculpture
32.19
60
180
68
2.0
TABLE III: Training time required to reach the same target PSNR on the INRIA Lytro dataset.
Setting
PSNR (dB) ↑
SSIM ↑
LPIPS ↓
w/o multi-res.
34.67 ± 3.21
0.90 ± 0.06
0.05 ± 0.03
w/o line prod.
35.46 ± 3.21
0.91 ± 0.05
0.04 ± 0.02
w/o 2D grid.
33.60 ± 3.26
0.87 ± 0.07
0.09 ± 0.05
Full model
37.61 ± 3.61
0.92 ± 0.05
0.04 ± 0.03
TABLE IV: Ablation study results on the INRIA Lytro dataset.
Levels
PSNR (dB) ↑
SSIM ↑
LPIPS ↓
Train. (min)
4 levels
36.10 ± 5.61
0.96 ± 0.02
0.02 ± 0.01
13
6 levels
36.91 ± 5.36
0.96 ± 0.01
0.02 ± 0.01
17
8 levels
37.30 ± 5.22
0.97 ± 0.01
0.01 ± 0.01
21
TABLE V: Impact of multi-resolution levels on the Stanford Gantry dataset.
Jagiellonian University, Faculty of Mathematics and Computer Science · IDEAS Research Institute · Poznań University of Technology, Institute of Robotics and Machine Intelligence
Mannheim Institute for Intelligent Systems in Medicine (MIISM) · Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany · Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University +2