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.
We present Light Field Primitives (LFP), a formulation for novel view synthesis that replaces the dense ray database with a compact set of differentiable primitives in the classical two-plane parameterization. Each primitive condenses a group of rays into one learned record, and its response to a query is governed by how closely that query belongs to the group. Rendering a camera ray then reduces to compositing all responses it elicits, and a scene can be optimized directly from posed images and rendered in real time with rays. Beyond its competitive performance on standard benchmarks, the main advantage of LFP is structural: its primitives reside directly in the 4D ray space, so optical and appearance effects that are already operations on the light field become behaviors of a single shared renderer. With minimal changes to that renderer, LFP supports multi-scale anti-aliasing, defocus deblurring with refocusing, rendering for fisheye cameras, and even transparent object reconstruction with ray refraction, matching specialized frameworks that devote substantial machinery to these effects.
Liang Chen, Jiahui Ning, Xun Jiang +4
Tongji University · Hong Kong Metropolitan University · City University of Hong Kong
Recent advances in neural scene representations enable photorealistic novel-view synthesis, yet most methods remain tightly coupled to a single rendering paradigm, limiting their versatility and integration with conventional graphics workflows. We introduce Floating Radiance Networks (FlaRe), a neural scene representation combining explicit ray-traceable geometry with continuous neural radiance functions. A scene is represented by floating planar generalized Gaussian primitives, each carrying a compact latent descriptor of a local radiance field. A lightweight decoder shared across the scene maps this descriptor, local surface coordinates, and viewing direction to color and opacity. This formulation preserves the expressiveness of neural fields while providing an explicitly addressable structure that can be efficiently queried and manipulated. Hardware-accelerated primitive intersections enable interactive rendering and recursive ray-tracing, including reflections, refractions, transparency, and shadows. The same representation further supports primitive-level deformation, mesh extraction, and appearance stylization directly in its learned descriptor space. Experiments across standard reconstruction benchmarks demonstrate competitive rendering quality while using a compact set of primitives. Together, these results establish FlaRe as a versatile representation that brings high-fidelity neural rendering, ray-tracing, geometric manipulation, and appearance editing into a unified scene model. Source code is available online. Source code can be found at: https://github.com/KByrski/FlaRe
Krzysztof Byrski, Rafał Tobiasz, Grzegorz Wilczyński +5
Jagiellonian University, Faculty of Mathematics and Computer Science · IDEAS Research Institute · Poznań University of Technology, Institute of Robotics and Machine Intelligence
Light-field disparity estimation requires global consistency in smooth or textureless regions and local precision near occlusion boundaries, thin structures, and abrupt depth transitions. Existing methods address these requirements through EPI matching, cost-volume or focal-stack construction, view aggregation, or direct convolutional regression, often relying on local windows, discrete disparity hypotheses, memory-intensive volumes, or attention-based aggregation. We instead formulate disparity estimation at the field level, predicting disparity from globally and locally updated EPI-derived latent features without explicitly constructing a disparity volume. We introduce FreqLF, an EPI-guided Fourier-local framework that encodes angular parallax cues from horizontal and vertical EPI stacks together with central-view appearance features. These cues are projected into a latent field and updated through stacked hybrid Fourier-local layers. Fourier low-mode updates enable global feature interaction, while local convolutions preserve spatial variations needed for fine disparity detail. A coordinate-conditioned Gaussian-mixture decoder then predicts disparity, using the mixture mean as the final estimate. Experiments on the HCI 4D Light Field Benchmark show that FreqLF approaches the accuracy of strong supervised baselines while avoiding explicit cost-volume construction in the base model. Ablations confirm the complementary roles of the Fourier and local branches, and scaling experiments demonstrate practical behavior across spatial resolutions. These results suggest that Fourier-local latent field learning is a competitive alternative for light-field disparity estimation. The code will be published soon.
Sara Monji-Azad, Yulin Liu, Jürgen Hesser
Mannheim Institute for Intelligent Systems in Medicine (MIISM) · Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany · Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University +2