中国激光, 2014, 41 (s1): s109004, 网络出版: 2014-07-03
自适应光学图像的频域幸运成像实验研究
Experiment Research of Lucky Imaging in Frequency Domain with Adaptive Optics Images
大气光学 自适应光学 高分辨率 幸运成像 图像融合 atmospheric optics adaptive optics high resolution lucky imaging image fusion
摘要
幸运成像技术是自适应光学(AO)图像高分辨率重建的一种事后处理技术。传统的幸运成像算法要先对短曝光图像进行像质评价,并选取像质最好的一些图像进行配准、叠加来重建目标图像,最终使得图像分辨率达到地基光学望远镜的衍射极限。但是传统幸运成像算法未考虑图像某些方向上的高分辨率信息,而频域幸运成像算法则在傅里叶频域内对每帧图像进行信息选取,可更有效地利用短曝光图像在不同方向上的高分辨率信息。仿真实验结果表明频域幸运成像算法与AO系统结合能克服大气湍流影响,明显提高望远镜的分辨能力。在没有AO校正的情况下对真实天文图像进行了处理,结果表明,频域幸运成像算法重建图像的分辨率高于传统幸运成像算法。
Abstract
Lucky imaging is a post processing technique which can reconstruct a high resolution image for adaptive optics. In classic lucky imaging algorithm, only a few images which meet the image quality criterion are selected, shifted and added to reconstruct a final image, with image resolution reaching diffraction limited resolution of the large ground-based optical telescopes. However, high resolution information in given direction of the unselected images is rejected as a result. As to the lucky imaging in frequency domain algorithm, the information is selected in Fourier domain for every frame. It selects Fourier complex values with highest amplitude values at each spatial frequency below the cut-off frequency. Therefore, it makes a more efficient use of high resolution information contained in the short exposure images. Simulation results show that lucky imaging in frequency domain can overcome the effect of the atmosphere turbulence and improve the ability of the telescope. The results on real world astronomical images show that the lucky imaging in frequency domain often yields final image of better quality than classic lucky imaging algorithm at an equivalent selection ratio without an adaptive optics system.
任晨纲, 梁永辉, 于起峰, 蒋鹏志. 自适应光学图像的频域幸运成像实验研究[J]. 中国激光, 2014, 41(s1): s109004. Ren Chengang, Liang Yonghui, Yu Qifeng, Jiang Pengzhi. Experiment Research of Lucky Imaging in Frequency Domain with Adaptive Optics Images[J]. Chinese Journal of Lasers, 2014, 41(s1): s109004.