基于伸缩梯度投影的天文图像复原改进算法

Improved astronomical image restoration algorithm based on scaled gradient projection

在地基天文观测中,克服大气湍流造成的图像模糊是获取高分辨率天文图像的关键。反卷积是图像复原过程中的重要步骤,基于伸缩梯度投影的反卷积算法具有较高的复原精度和处理效率,且鲁棒性好,适用于天文图像的复原。但由于实际应用中清晰图像是未知的且存在噪声的干扰,该算法存在着无法自行停止迭代的弊端,限制了其应用。结合图像无参考质量度量给出一种可自动停止迭代的改进算法。仿真表明:改进的算法对最优点判断较为准确,能够运用于实际天文图像处理。

In ground-based astronomy observation,overcome image blurring caused by atmosphere turbulence is key to obtain high-resolution astronomical images. Deconvolution is an important step in process of image restoration,and deconvolution algorithm based on scaled gradient projection is suitable for astronomical image restoration with high recovery precision,processing efficiency,and good robustness. But in practice,the clear images are unknown and interferences caused by noise exist,the algorithm is unable to stop iteration,making its application limited. Combined with no-reference quality measurement,an improved algorithm which can automatically stop iteration is proposed. Simulation indicates that the improved algorithm can accurately judge the optimal point and can be applied to real astronomical image processing.