Journal of Computer Applications ›› 2025, Vol. 45 ›› Issue (1): 204-213.DOI: 10.11772/j.issn.1001-9081.2023121726

• Multimedia computing and computer simulation • Previous Articles     Next Articles

Dual-branch network guided by local entropy for dynamic scene high dynamic range imaging

Ying HUANG1,2(), Changsheng LI1, Hui PENG2, Su LIU2   

  1. 1.College of Computer Science and Technology,Chongqing University of Posts and Telecommunications,Chongqing 400065,China
    2.School of Software Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China
  • Received:2023-12-15 Revised:2024-02-27 Accepted:2024-03-04 Online:2024-04-10 Published:2025-01-10
  • Contact: Ying HUANG
  • About author:LI Changsheng, born in 1999, M. S. candidate. His research interests include multi-exposure image fusion.
    PENG Hui, born in 1998, M. S. candidate. Her research interests include image enhancement.
    LIU Su, born in 1990, Ph. D., lecturer. Her research interests include radar target recognition, SAR image processing, video behavior recognition.

用于动态场景高动态范围成像的局部熵引导的双分支网络

黄颖1,2(), 李昌盛1, 彭慧2, 刘苏2   

  1. 1.重庆邮电大学 计算机科学与技术学院,重庆 400065
    2.重庆邮电大学 软件工程学院,重庆 400065
  • 通讯作者: 黄颖
  • 作者简介:李昌盛(1999—),男,河南信阳人,硕士研究生,主要研究方向:多曝光图像融合;
    彭慧(1998—),女,重庆人,硕士研究生,主要研究方向:图像增强;
    刘苏(1990—),女,山东菏泽人,讲师,博士,主要研究方向:雷达目标识别、SAR图像处理、视频行为识别。

Abstract:

For addressing the issues of motion artifacts and exposure distortion in High Dynamic Range (HDR) imaging tasks based on a sequence of multiple exposed images when there is camera shake or subject movement, a dual-branch network guided by local entropy for dynamic scene HDR imaging was proposed. Firstly, the Discrete Wavelet Transform (DWT) was employed to separate the low-frequency illumination-related information and high-frequency motion-related information from the input images, enabling the network to address exposure and subject movement purposefully. Secondly, for the low-frequency illumination-related information branch, a module was designed to calculate attention using image local entropy, thereby guiding the network to reduce the extraction of exposure features lacking details. For the high-frequency motion-related information branch, a lightweight feature alignment module was introduced for consistent alignment of scene, thereby reducing the extraction of motion features. Finally, a time-domain self-attention module was constructed by integrating channel attention, thereby enhancing the mutual dependence of exposure image sequence in temporal domain, so as to further improve the quality of the results. Evaluation was performed on public datasets Kalantari, Sen, and Tursun. Experimental results on Kalantari dataset show that the proposed network achieves the first place in PSNR-l (42.20 dB) and the third place in SSIM-l (0.988 9) compared to some latest methods. By integrating experimental results on the remaining datasets, it can be seen that the proposed network can reduce exposure distortion and motion artifacts effectively, and generate images with abundant details and excellent visual effect.

Key words: High Dynamic Range (HDR) imaging, local entropy, attention mechanism, Discrete Wavelet Transform (DWT), image information separation

摘要:

针对基于多张曝光图像序列的高动态范围(HDR)成像任务在相机抖动或拍摄主体移动时出现运动伪影以及曝光失真的问题,提出一个用于动态场景HDR成像的局部熵引导的双分支网络。首先,利用离散小波变换(DWT)分离出输入图像的低频光照相关信息以及高频运动相关信息,以便于网络有针对性地处理曝光以及主体移动;其次,对于低频光照相关信息分支,设计一个利用图像局部熵计算注意力的模块来引导网络减少细节不足的曝光特征的提取;对于高频运动相关信息分支,引入一个轻量级的特征对齐模块来进行场景的一致性对齐,从而减少运动特征的提取;最后,结合通道注意力构建时域自注意力模块,从而加强曝光图像序列在时间域之间的相互依赖关系,以进一步提高结果质量。在公开数据集Kalantari、Sen、Tursun上进行评估。在Kalantari数据集上的实验结果表明,与最新的一些方法对比,所提网络以PSNR-l为42.20 dB的成绩取得第一,SSIM-l为0.988 9的成绩取得第三。结合其余数据集上的实验结果可知,所提网络可以有效减少曝光失真以及运动伪影,并生成细节多、视觉效果佳的图像。

关键词: 高动态范围成像, 局部熵, 注意力机制, 离散小波变换, 图像信息分离

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