水下热扰动的光学成像失真问题研究  

Study on optical imaging distortion of underwater thermal disturbance

作　　者：王从政[1,2,3] 胡松 高椿明[2] 冯常 Wang Congzheng;Hu Song;Gao Chunming;Feng Chang(Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, Sichuan 610209, China;School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院光电技术研究所,四川成都610209 [2]电子科技大学光电科学与工程学院,四川成都610054 [3]中国科学院大学,北京100049

出　　处：《光电工程》2019年第10期1-9,共9页Opto-Electronic Engineering

基　　金：国家自然科学基金资助项目(61675206)~~

摘　　要：为了研究水下热扰动环境对光学成像的畸变、模糊等失真问题的影响,利用水下图像的灰度分布、结构相似性图像度量(SSIM)和归一化最大灰度梯度清晰度评价函数来评价目标图像在径向和轴向上的畸变和模糊等失真程度,得到水下热扰动对光学成像变化的规律。实验数据表明,随着成像系统与目标的轴向距离增加,图像的畸变和模糊程度越来越大。轴向距离L1=500mm时,对应图像的SSIM值优于0.7,归一化清晰度值优于0.8;轴向距离L3=1500mm时,对应图像的SSIM值低于0.2,归一化清晰度值不足0.6;此外,轴向距离L1时,成像在径向上,距离发热源越近,边缘漂移越大,即成像图像畸变越严重;最后,相同轴向和径向条件下,目标在不同时刻的图像SSIM和归一化清晰度值有优劣,该结论可为后续的水下图像复原提供参考。In order to study the influence of underwater thermal disturbance environment on imaging distortion, such as optical imaging distortion or imaging blur, the level of distortion of target image in radial and axial directions was evaluated by using the gray scale distribution, structural similarity image measurement (SSIM), and normalized maximum gray-scale gradient definition evaluation function of underwater images. Furthermore, the laws of underwater thermal disturbance on optical imaging changes were obtained. Experimental results show that with the increase of the axial distance between the imaging system and the target, the level of image distortion and blurring becomes larger and larger. When the axial distance is equal to 500 mm, the SSIM is better than 0.7 and the normalized definition is better than 0.8. When the axial distance reaches 1500 mm, the SSIM is lower than 0.2 and the normalized definition is less than 0.6. In addition, when the axial distance equals 500 mm, the drift of the edges will be greater as the imaging area comes closer the heating source in the radial direction, that is, the imaging distortion is more serious. Finally, under the same axial and radial conditions, the conclusion that the SSIM and normalized definition values of the target images are different at different times can provide a reference for further underwater image restoration.

关 键 词：水下成像 热扰动 图像畸变 图像模糊 图像评价 

分 类 号：TH711[机械工程—测试计量技术及仪器]