Papers › Non-Local Recurrent Network for Image Restoration

Non-Local Recurrent Network for Image Restoration

7 Jun 2018NeurIPS 2018 12arXiv:1806.02919archive 2025-07-28

Ding Liu, Bihan Wen, Yuchen Fan, Chen Change Loy, Thomas S. Huang

Many classic methods have shown non-local self-similarity in natural images to be an effective prior for image restoration. However, it remains unclear and challenging to make use of this intrinsic property via deep networks. In this paper, we propose a non-local recurrent network (NLRN) as the first attempt to incorporate non-local operations into a recurrent neural network (RNN) for image restoration. The main contributions of this work are: (1) Unlike existing methods that measure self-similarity in an isolated manner, the proposed non-local module can be flexibly integrated into existing deep networks for end-to-end training to capture deep feature correlation between each location and its neighborhood. (2) We fully employ the RNN structure for its parameter efficiency and allow deep feature correlation to be propagated along adjacent recurrent states. This new design boosts robustness against inaccurate correlation estimation due to severely degraded images. (3) We show that it is essential to maintain a confined neighborhood for computing deep feature correlation given degraded images. This is in contrast to existing practice that deploys the whole image. Extensive experiments on both image denoising and super-resolution tasks are conducted. Thanks to the recurrent non-local operations and correlation propagation, the proposed NLRN achieves superior results to state-of-the-art methods with much fewer parameters.

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Tasks

DenoisingFeature CorrelationImage DenoisingImage RestorationImage Super-ResolutionSuper-Resolution

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Denoising Darmstadt Noise Dataset NLRN PSNR 30.8 #10 of 10 Archive leaderboard report
Grayscale Image Denoising BSD200 sigma30 NLRN-MV PSNR 28.2 #2 of 3 Archive leaderboard report
Grayscale Image Denoising BSD200 sigma50 NLRN-MV PSNR 25.97 #2 of 3 Archive leaderboard report
Grayscale Image Denoising BSD200 sigma70 NLRN-MV PSNR 24.62 #2 of 3 Archive leaderboard report
Grayscale Image Denoising BSD68 sigma15 NLRN PSNR 31.88 #5 of 16 Archive leaderboard report
Grayscale Image Denoising BSD68 sigma25 NLRN PSNR 29.41 #3 of 16 Archive leaderboard report
Grayscale Image Denoising BSD68 sigma50 NLRN PSNR 26.47 #5 of 15 Archive leaderboard report
Grayscale Image Denoising Set12 sigma15 NLRN PSNR 33.16 #3 of 8 Archive leaderboard report
Grayscale Image Denoising Set12 sigma30 NLRN PSNR 30.8 #1 of 2 Archive leaderboard report
Grayscale Image Denoising Set12 sigma50 NLRN PSNR 27.64 #4 of 8 Archive leaderboard report
Grayscale Image Denoising Urban100 sigma15 NLRN PSNR 33.45 #4 of 7 Archive leaderboard report
Grayscale Image Denoising Urban100 sigma25 NLRN PSNR 30.94 #7 of 10 Archive leaderboard report
Grayscale Image Denoising Urban100 sigma50 NLRN PSNR 27.49 #6 of 10 Archive leaderboard report
Image Super-Resolution BSD100 - 4x upscaling NLRN PSNR 27.48 #38 of 71 Archive leaderboard report
Image Super-Resolution BSD100 - 4x upscaling NLRN SSIM 0.7306 #38 of 71 Archive leaderboard report
Image Super-Resolution Set14 - 4x upscaling NLRN PSNR 28.36 #70 of 104 Archive leaderboard report
Image Super-Resolution Set14 - 4x upscaling NLRN SSIM 0.7745 #70 of 104 Archive leaderboard report
Image Super-Resolution Urban100 - 4x upscaling NLRN PSNR 25.79 #47 of 65 Archive leaderboard report
Image Super-Resolution Urban100 - 4x upscaling NLRN SSIM 0.7729 #47 of 65 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

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