Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain

With the advent of deep learning, significant progress has been made in low-light image enhancement methods. However, deep learning requires enormous paired training data, which is challenging to capture in real-world scenarios. To address this limitation, this paper presents a novel unsupervised lo...

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Main Authors: Xupei Zhang, Hanlin Qin, Yue Yu, Xiang Yan, Shanglin Yang, Guanghao Wang
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/15/14/3580
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author Xupei Zhang
Hanlin Qin
Yue Yu
Xiang Yan
Shanglin Yang
Guanghao Wang
author_facet Xupei Zhang
Hanlin Qin
Yue Yu
Xiang Yan
Shanglin Yang
Guanghao Wang
author_sort Xupei Zhang
collection DOAJ
description With the advent of deep learning, significant progress has been made in low-light image enhancement methods. However, deep learning requires enormous paired training data, which is challenging to capture in real-world scenarios. To address this limitation, this paper presents a novel unsupervised low-light image enhancement method, which first introduces the frequency-domain features of images in low-light image enhancement tasks. Our work is inspired by imagining a digital image as a spatially varying metaphoric “field of light”, then subjecting the influence of physical processes such as diffraction and coherent detection back onto the original image space via a frequency-domain to spatial-domain transformation (inverse Fourier transform). However, the mathematical model created by this physical process still requires complex manual tuning of the parameters for different scene conditions to achieve the best adjustment. Therefore, we proposed a dual-branch convolution network to estimate pixel-wise and high-order spatial interactions for dynamic range adjustment of the frequency feature of the given low-light image. Guided by the frequency feature from the “field of light” and parameter estimation networks, our method enables dynamic enhancement of low-light images. Extensive experiments have shown that our method performs well compared to state-of-the-art unsupervised methods, and its performance approximates the level of the state-of-the-art supervised methods qualitatively and quantitatively. At the same time, the light network structure design allows the proposed method to have extremely fast inference speed (near 150 FPS on an NVIDIA 3090 Ti GPU for an image of size <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>600</mn><mo>×</mo><mn>400</mn><mo>×</mo><mn>3</mn></mrow></semantics></math></inline-formula>). Furthermore, the potential benefits of our method to object detection in the dark are discussed.
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spelling doaj.art-7ef7220041024106bc30238ed50663bc2023-11-18T21:12:49ZengMDPI AGRemote Sensing2072-42922023-07-011514358010.3390/rs15143580Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency DomainXupei Zhang0Hanlin Qin1Yue Yu2Xiang Yan3Shanglin Yang4Guanghao Wang5School of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi’an 710071, ChinaWith the advent of deep learning, significant progress has been made in low-light image enhancement methods. However, deep learning requires enormous paired training data, which is challenging to capture in real-world scenarios. To address this limitation, this paper presents a novel unsupervised low-light image enhancement method, which first introduces the frequency-domain features of images in low-light image enhancement tasks. Our work is inspired by imagining a digital image as a spatially varying metaphoric “field of light”, then subjecting the influence of physical processes such as diffraction and coherent detection back onto the original image space via a frequency-domain to spatial-domain transformation (inverse Fourier transform). However, the mathematical model created by this physical process still requires complex manual tuning of the parameters for different scene conditions to achieve the best adjustment. Therefore, we proposed a dual-branch convolution network to estimate pixel-wise and high-order spatial interactions for dynamic range adjustment of the frequency feature of the given low-light image. Guided by the frequency feature from the “field of light” and parameter estimation networks, our method enables dynamic enhancement of low-light images. Extensive experiments have shown that our method performs well compared to state-of-the-art unsupervised methods, and its performance approximates the level of the state-of-the-art supervised methods qualitatively and quantitatively. At the same time, the light network structure design allows the proposed method to have extremely fast inference speed (near 150 FPS on an NVIDIA 3090 Ti GPU for an image of size <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>600</mn><mo>×</mo><mn>400</mn><mo>×</mo><mn>3</mn></mrow></semantics></math></inline-formula>). Furthermore, the potential benefits of our method to object detection in the dark are discussed.https://www.mdpi.com/2072-4292/15/14/3580low-light image enhancementunsupervised learningphysics-inspired computer vision
spellingShingle Xupei Zhang
Hanlin Qin
Yue Yu
Xiang Yan
Shanglin Yang
Guanghao Wang
Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
Remote Sensing
low-light image enhancement
unsupervised learning
physics-inspired computer vision
title Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
title_full Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
title_fullStr Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
title_full_unstemmed Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
title_short Unsupervised Low-Light Image Enhancement via Virtual Diffraction Information in Frequency Domain
title_sort unsupervised low light image enhancement via virtual diffraction information in frequency domain
topic low-light image enhancement
unsupervised learning
physics-inspired computer vision
url https://www.mdpi.com/2072-4292/15/14/3580
work_keys_str_mv AT xupeizhang unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain
AT hanlinqin unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain
AT yueyu unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain
AT xiangyan unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain
AT shanglinyang unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain
AT guanghaowang unsupervisedlowlightimageenhancementviavirtualdiffractioninformationinfrequencydomain