卫星振动引起的非规则采样降质图像复原方法

Restoration of irregularly sampled image degradation due to satellite vibrations

针对卫星振动引起的TDICCD相机非规则采样导致像质退化的问题,提出了非规则采样降质退化图像的复原方法.首先利用基于非均匀快速傅里叶变换的频域插值对非规则采样的几何降质退化规律进行建模,并结合遥感成像的模糊退化过程,建立非规则采样降质图像退化模型.然后利用频域插值特性将模型逆求解过程转换为Toeplitz矩阵系统的线性方程求解问题,实现了快速求解,提出非规则采样几何降质和模糊退化的综合处理方法.最后利用测试图形和真实遥感图像对方法进行验证,实验结果表明:在严重模糊、几何降质及高噪声水平条件下,复原后的图像与理想图像的结构相似度仍优于0.93,而且具有较高的处理效率.该方法能有效应用于在轨振动引起的非规则采样降质的复原处理.

A new method is proposed to solve a problem of image restoration which would be degraded by TDICCD irregular sampling process owning to satellite vibrations.Firstly,the rules of image geometric quality degradation is mathematically modeled using unequally spaced fast Fourier transform（ USFFT） interpolation,and then a full image degradation model is developed combined with the blurred degradation process.Subsequently,the inverse solution problem of the model equations is transformed into a system of linear equations with a Toeplitz matrix as system matrix on the basis of the USFFT interpolation characteristics.And then the equations can be sovled efficiently.Then,a new method of image restoration is presented,which can implement not only deblurring but also irregular to regular sampling.Finally,the method is verified using simulated standard pattern and real remote sensing images.Experimental results indicate that the proposed method is able to improve the irregularly sampled image effectively,and it has fast computation.The Structural Similarity index between the restored and ideal images is no less than 0.93 in the case of seriously blurred,irregularly sampled and noisy images.The proposed approach can be applied to restore the irregular sampling images owning to on-orbit vibrations effectively.