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投稿时间:2021-07-02 修订日期:2022-09-19
投稿时间:2021-07-02 修订日期:2022-09-19
中文摘要: 图像复原是一个重要的底层视觉问题,旨在从低质量图像中恢复出高质量图像。虽然,近年来基于深度学习的方法在图像复原领域展现出了优秀的性能,但是,大多数深度网络均是基于经验进行结构设计,较少考虑与现有的传统算法进行融合,因此网络可解释性较差。针对上述问题,本文提出了一种基于小波域ADMM深度网络的图像复原算法。首先,将小波变换同步引入到数据项以及先验项,提出了小波域下的图像复原模型,将图像复原问题变换到小波域进行研究,构建新的图像退化模型和复原代价函数。然后,为了有效降低该问题的优化求解难度,提出引入ADMM算法将其进一步分解为更易处理的复原子问题和去噪子问题分别求解,通过不断优化得到小波域图像最佳估计。最后,基于上述优化过程解的具体形式指导构建深度卷积神经网络,实现端到端的图像复原。该网络由于是在小波域进行图像处理,使得网络感受野增加且网络中特征映射的空间尺寸缩小。不仅能获得更好的性能,而且大幅降低了运算复杂度、提高了处理速度。将上述网络应用于图像去模糊和图像去噪任务,在Set10、BSD68和Urban100数据集上验证复原性能。相关实验结果表明,本文提出的算法对于去模糊和去噪任务都能取得较好的复原效果,其PSNR值增加0.08~0.18 dB,同时结果图片保留更多的细节信息,因此无论是定量还是定性结果都优于对比算法。
Abstract:In recent years, deep learning-based methods have shown excellent performance in the field of image restoration. However, most deep networks are structured based on experience, and less consideration is given to fusion with existing traditional algorithms, therefore these networks arepoorly interpretable. To address this problem, an image restoration algorithm based on wavelet domain ADMM deep networkwasproposed. Firstly, a wavelet transform is introduced to the data term as well as the prior term simultaneously, an image recovery model under wavelet domain was proposed. Consequently the image recovery problem was transformed from spatial domain into wavelet domain, and a new image degradation model and recovery cost function were constructed. Then, in order to effectively reduce the difficulty of the optimal solution, the ADMM algorithm was introduced to further decompose it into a more manageable restoration subproblem and a denoising subproblem, and obtain the best estimate of the wavelet domain image through continuous optimization. Finally, the specific form of the solution based on the above optimization process guides the construction of a deep convolutional neural network to achieve end-to-end image recovery. The perceptual field and spatial feature mappingsizeof this networkis increased and decreased respectivelysince the image processing was executed in the wavelet domain. Not only does it achieve better performance, but also significantly reduces the complexity of operations and increases the processing speed. The proposed network was applied to image deblurring and image denoising tasks to verify the recovery performance on Set10, BSD68 and Urban100 datasets. The relevant experimental results show that the proposed algorithm achieves better recovery results for both deblurring and denoising tasks, with an increase of 0.08~0.18 dB in PSNR values while the resultant images retain more detailed information, thus outperforming the comparison methods in both quantitative and qualitative results.
文章编号:202100642 中图分类号:TN911.7 文献标志码:
基金项目:国家自然科学基金项目(62171304);四川省重点研发计划项目(2022YFS0098);上海航天科技创新基金项目(SAST2019-027)
作者简介:第一作者:卿粼波(1982—),男,教授. 研究方向:图像处理、视频编码. E-mail:qing_lb@scu.edu.cn;通信作者:任超, E-mail:chaoren@scu.edu.cn
引用文本:
卿粼波,吴梦凡,刘刚,刘晓,何小海,任超.基于小波域ADMM深度网络的图像复原算法[J].工程科学与技术,2022,54(5):257-267.
QING Linbo,WU Mengfan,LIU Gang,LIU Xiao,HE Xiaohai,REN Chao.Deep ADMM Network in Wavelet Domain for Image Restoration[J].Advanced Engineering Sciences,2022,54(5):257-267.
引用文本:
卿粼波,吴梦凡,刘刚,刘晓,何小海,任超.基于小波域ADMM深度网络的图像复原算法[J].工程科学与技术,2022,54(5):257-267.
QING Linbo,WU Mengfan,LIU Gang,LIU Xiao,HE Xiaohai,REN Chao.Deep ADMM Network in Wavelet Domain for Image Restoration[J].Advanced Engineering Sciences,2022,54(5):257-267.