一种星载面阵相机序列影像的系统噪声去除方法

A System Noise Removal Method for Series Images from Spaceborne Area Array Camera

  • 摘要: 由于面阵相机在轨辐射定标困难,当相对辐射定标系数不够准确或者卫星状态发生变化时,面阵成像遥感影像中会出现大量系统噪声。本文分析了系统噪声的来源,并基于序列影像系统噪声在时间轴上存在相关性的特点,提出了一种利用序列影像去除系统噪声的方法。本方法首先将原始影像与高斯滤波后的影像进行比值运算以去除辐射特征,得到纹理图像;然后将圆形局部二值模式(local binarypattern,LBP)算子和格拉布斯(Grubbs)准则结合滤除梯度特征,获得噪声图像;利用序列噪声图像叠加得到校正系数,实现系统噪声的去除。以模拟和真实获取的噪声图像作为实验数据,采用多种去噪方法进行对比实验,结果表明本文方法能够在去除噪声的同时,有效保留影像的边缘细节和纹理信息。

     

    Abstract: Objectives: Due to the difficulty of the on-orbit radiometric calibration of area-array camera, a large amount of system noise will appear in the area-array imaging remote sensing images when the relative radiometric calibration coefficients are not accurate enough or the satellite state changes. Most of the existing denoising methods are based on the spatial domain correlation or transform domain correlation of images, and the denoising images will have the problem of losing edge details and texture characteristics. We analyzes the source of the system noise and proposes a method to remove system noise using series images based on the correlation of system noise in the time axis of series images. Methods: First, the original image and the Gaussian filtered image are firstly combined in a ratio operation to eliminate the radiation characteristics to obtain multiple texture images. Second, the circular local binary pattern (LBP) operator and Grubbs criterion are combined to eliminate the gradient characteristics to obtain multiple noise images. Third, the correction coefficients are obtained by the superposition of multiple noise images, and further used to filter out the system noise. Results: The simulated and real images are used as the experimental data. Our proposed method was compared with non-local mean(NLM), discrete cosine transform(DCT), wavelet thresholding denoising, weighted nuclear norm minimization(WNNM), and block matching 3-D filtering(BM3D). Our method obtains the highest peak signal-to-noise ratio(PSNR) and structural similarity index(SSIM) with different noise levels in simulation experiments. For real data experiment, the laboratory coefficient correction, DCT and wavelet thresholding can not remove the noise well. BM3D and WNNM can efficiently remove noise and obtain high signal-to-noise ratio(SNR), but the edge and texture details are lost seriously. Our method removes the noise very well, and it can maintain the edge details and texture information. Conclusions: The results show that the method in this paper can effectively maintain image edge details and texture information while removing image noise.

     

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