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FS-NCSR: Increasing Diversity of the Super-Resolution Space via Frequency Separation and Noise-Conditioned Normalizing Flow

20 Apr 2022arXiv:2204.09679archive 2025-07-28

Ki-Ung Song, Dongseok Shim, Kang-wook Kim, Jae-young Lee, Younggeun Kim

Super-resolution suffers from an innate ill-posed problem that a single low-resolution (LR) image can be from multiple high-resolution (HR) images. Recent studies on the flow-based algorithm solve this ill-posedness by learning the super-resolution space and predicting diverse HR outputs. Unfortunately, the diversity of the super-resolution outputs is still unsatisfactory, and the outputs from the flow-based model usually suffer from undesired artifacts which causes low-quality outputs. In this paper, we propose FS-NCSR which produces diverse and high-quality super-resolution outputs using frequency separation and noise conditioning compared to the existing flow-based approaches. As the sharpness and high-quality detail of the image rely on its high-frequency information, FS-NCSR only estimates the high-frequency information of the high-resolution outputs without redundant low-frequency components. Through this, FS-NCSR significantly improves the diversity score without significant image quality degradation compared to the NCSR, the winner of the previous NTIRE 2021 challenge.

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deriveScaleFromSize dsshim0125/FS-NCSR/imresize.py official repository ran MIT (permissive) · b97b2d33b67260a8 · report
deriveSizeFromScale dsshim0125/FS-NCSR/imresize.py official repository ran MIT (permissive) · ffe34bf756a6eaa8 · report
fiFindByWildcard dsshim0125/FS-NCSR/measure.py official repository ran fingerprinted MIT (permissive) · 2a857e38ee87f92c · report
imread dsshim0125/FS-NCSR/prepare_data.py official repository ran MIT (permissive) · d4a4924746094263 · report
imread dsshim0125/FS-NCSR/measure.py official repository ran MIT (permissive) · ff6d805555b31561 · report
random_crop dsshim0125/FS-NCSR/prepare_data.py official repository ran fingerprinted MIT (permissive) · 9c54ab0c75133028 · report
t dsshim0125/FS-NCSR/measure.py official repository ran MIT (permissive) · 6a8e1704755f6a34 · report
triangle dsshim0125/FS-NCSR/imresize.py official repository ran fingerprinted MIT (permissive) · 2722f476a816c1b9 · report
define_Flow dsshim0125/FS-NCSR/models/networks.py official repository unverified MIT (permissive) · 6d050c5262a0b80b · report
find_model_using_name dsshim0125/FS-NCSR/models/networks.py official repository unverified MIT (permissive) · 7d04d276ed855e64 · report

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