Method for detecting changes of SAR images based on multi-scale product and principal component analysis

Abstract

The invention discloses a method for detecting changes of SAR (synthetic aperture radar) images on the basis of multi-scale product and principal component analysis ( PCA ), mainly solving the problems that the adaptability is poor, the application range is narrow and the change detection results are subject to image misregistration. The method comprises the following specific implementation procedures: firstly, conducting the logarithmic ratio operation on two inputted time phase SAR images to obtain a difference image; carrying out the wavelet transform on the difference image; carrying out the multi-scale product de-noising on the high-frequency information of each decomposition layer; then, combining the de-noised images of each layer and carrying out the PCA transform, wherein, a first PCA image is used as a new difference image; and finally classifying the new difference image by using the minimum error ratio threshold value of the generalized Gaussian model to obtain the final result image of changes. The experiment shows that the invention can enhance the change information, have strong antinoise performance and reduce the influence of image misregistration, thus having high applicability and can be applied to the disaster detection of SAR images.

Description

Technical field: [0001] The invention belongs to the technical field of digital image processing, specifically a method for detecting changes in SAR images based on multi-scale product sum principal component analysis, which is suitable for remote sensing image processing and analysis. Background technique [0002] The change detection of remote sensing images refers to the analysis of remote sensing images of the same geographical location in different periods to obtain the change information. Since Synthetic Aperture Radar (SAR) has the ability to obtain surface information all-weather and all-weather, and has a certain penetration ability, the interpretation and application of SAR images has become a hot issue in the research of modern remote sensing technology. SAR image change detection technology realizes continuous reconnaissance in civil fields such as positioning of earthquake areas and disaster assessment, as well as battlefield areas or key surveillance targets. I...

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Problems solved by technology

However, the disadvantage of this method is that the final change detection result is affected by the location of change information in the low frequency of a certain decomposition layer and the location accuracy of the local maximum, which limits the applicability of the method.

[0007] 3. Zhang Hui and other scholars proposed a SAR image change detection method based on principal component analysis, in which the two-temporal images were decomposed by principal component analysis, and through mathematical derivation and theoretical analysis, it was found that the principal components mainly represented the unchanged changes of the two images part, and the subcomponent can be used to characterize the changing part of the image. Although this method has strong anti-speckle noise, the result is easily affected by image misregistration, and there are a lot of false change information in the detected change results.

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