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arXiv 2402.09561cs.CVeess.IV
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基于块的自适应时间滤波器与残差评估

Patch-based adaptive temporal filter and residual evaluation

Télécom ParisTech, Université Paris-Saclay(巴黎萨克雷大学电信学院);IMB, CNRS, Univ. Bordeaux, Bordeaux INP(波尔多大学波尔多综合理工学院国家科学研究中心数学与计算机科学研究所);Univ Lyon, UJM-Saint-Etienne, CNRS, Institut d Optique Graduate School, Laboratoire Hubert Curien UMR 5516(里昂大学圣埃蒂安大学国家科学研究中心光学研究所于贝尔·屈里安实验室)

Weiying Zhao, Paul Riot, Charles-Alban Deledalle, Henri Maître, Jean-Marie Nicolas, Florence Tupin

AI总结:

针对相干成像中的散斑噪声,提出基于块的自适应时间滤波器(PATF),利用多时相SAR图像进行去噪,并提出无参考图像的自协方差残差评估方法,验证了方法的有效性与实用性。

摘要:

在相干成像系统中,散斑是一种依赖于信号的噪声,在视觉上会强烈降低图像的外观质量。已经从不同传感器获取了大量具有不同波长、分辨率、入射角和极化方式的SAR数据。我们将非局部滤波策略扩展到时间域,并提出一种基于块的自适应时间滤波器(PATF),以利用配准良好的多时相SAR图像。通过处理基于块的广义似然比检验,来抑制变化目标对多时相去噪结果的影响。随后,利用指数函数将相似度转换为相应的权重。去噪值通过时间加权平均来计算。当时间序列有限时,空间自适应去噪方法可以改进基于块加权的时间平均图像。当时间序列足够大时,空间自适应去噪步骤是可选的。在没有参考图像的情况下,我们提出使用一种基于块的自协方差残差评估方法,来检查噪声图像与去噪图像之间的比值图像,并寻找可能残留的结构内容。该方法可以自动处理,且不依赖于同质区域的监督选择。它还为整幅图像提供了一个全局评分。大量结果证明了所提出的时间序列去噪方法的有效性以及残差评估方法的实用性。

英文摘要:

In coherent imaging systems, speckle is a signal-dependent noise that visually strongly degrades images' appearance. A huge amount of SAR data has been acquired from different sensors with different wavelengths, resolutions, incidences and polarizations. We extend the nonlocal filtering strategy to the temporal domain and propose a patch-based adaptive temporal filter (PATF) to take advantage of well-registered multi-temporal SAR images. A patch-based generalised likelihood ratio test is processed to suppress the changed object effects on the multitemporal denoising results. Then, the similarities are transformed into corresponding weights with an exponential function. The denoised value is calculated with a temporal weighted average. Spatial adaptive denoising methods can improve the patch-based weighted temporal average image when the time series is limited. The spatial adaptive denoising step is optional when the time series is large enough. Without reference image, we propose using a patch-based auto-covariance residual evaluation method to examine the ratio image between the noisy and denoised images and look for possible remaining structural contents. It can process automatically and does not rely on a supervised selection of homogeneous regions. It also provides a global score for the whole image. Numerous results demonstrate the effectiveness of the proposed time series denoising method and the usefulness of the residual evaluation method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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