Sparse-DeRF: Deblurred Neural Radiance Fields from Sparse View

Under Review

Yonsei University    
† Corresponding author
(a) Ground truth with annotation
(b) DP-NeRF
(c) RegNeRF(DP)
(d) Ours
(e) Ground truth
Interactive visualization. Hover or tap to move the zoom cursor.

Sparse-DeRF regularizes the complex joint optimization of blur kernel and neural radiance fields under sparse blurry images, improving geometric structure and sharp texture.

We present the reconstructed clean deblurred neural radiance fields (DeRF) from 3 types of sparse views: 2-view, 4-view, and 6-view, which is carefully selected environmal setting based on comprehensive experiments. We apply our method based on two types of representative blur kernels from Deblur-NeRF and DP-NeRF (b). Previously proposed representative regularization technique, RegNeRF (c), could not enhance the correct geometric structure and sharp texture of the scene due to the complex optimization issue of the blurkernel from DP-NeRF and radiance fields. Our proposed method (d) successfully regularizes the complex optimization and shows high-fidelity with high quality rendered images and videos.


Abstract

Recent studies construct deblurred neural radiance fields (DeRF) using dozens of blurry images, which are not practical scenarios if only a limited number of blurry images are available. This paper focuses on constructing DeRF from sparse- view for more pragmatic real-world scenarios.

As observed in our experiments, establishing DeRF from sparse views proves to be a more challenging problem due to the inherent complexity arising from the simultaneous optimization of blur kernels and NeRF from sparse view. Sparse-DeRF successfully regularizes the complicated joint optimization, presenting alleviated overfitting artifacts and enhanced quality on radiance fields. The regularization consists of three key components: Surface smoothness, helps the model accurately predict the scene structure utilizing unseen and additional hidden rays derived from the blur kernel based on statistical tendencies of real-world; Modulated gradient scaling, helps the model adjust the amount of the backpropagated gradient according to the arrangements of scene objects; Perceptual distillation improves the perceptual quality by overcoming the ill- posed multi-view inconsistency of image deblurring and distilling the pre-filtered information, compensating for the lack of clean information in blurry images.

We demonstrate the effectiveness of the Sparse-DeRF with extensive quantitative and qualitative experimental results by training DeRF from 2-view, 4-view, and 6-view blurry images.


Complex Optimization Issue

Architecture

The graph present expeirmental results according the number of blurry images from 2-view to 10-view. The result demonstrates the joint optimization problem of blur kernel and neural radiance fields from sparse views. The optimization issue occurs under the 9-view, which lead to suboptimal when apply the existing regularization technique. Therefore, we set the practical sparse view settings as 2-view, 4-view, and 6-view.


Visual Comparison

Interactive visualization. Hover or tap to move the zoom cursor.

(a) Ground truth with annotation
(b) DP-NeRF
(c) RegNeRF (DP)
(d) Ours
(e) Ground truth
Rendered color and depth results from 2-view.
(a) Ground truth with annotation
(b) DP-NeRF
(c) RegNeRF (DP)
(d) Ours
(e) Ground truth
Rendered color and depth results from 4-view
(a) Ground truth with annotation
(b) DP-NeRF
(c) RegNeRF (DP)
(d) Ours
(e) Ground truth
Rendered color and depth results from 6-view

The rendered RGB and depth images from 2-view, 4-view, and 6-view blurry images are presented with zoom-in to compare the visual quality. It is prominent that RegNeRF (c) with blur kernel fails to grasp the accurate geometry and appearance due to the simultaneous complex optimization. The performance of RegNeRF (DP) often shows even worse results than DP-NeRF (b). However, our proposed method (d) shows prominently enhanced quality in both geometry and appearance.


Video Comparisons to Previous Regularization Method

We show the visual comparisons between RegNeRF with DP kernel and Sparse-DeRF through the rendered RGB and depth videos. The videos demonstrate that previous regularization technique rather make the reconstruction quality of radiance fields worse on the sparse blurry environments, suffering geometric inaccuracy. However, the results of Sparse-DeRF shows that our proposed method successfully regularize the joint optimization and enhance the geometric and appearnce quality. Please click the tabs to see the visual comparisons on each scene.

(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)
(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)
(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)
(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)
(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)
(a) RegNeRF (w/ DP kernel)
(b) Sparse-DeRF (Ours)