A SAR image speckle suppression method

Abstract

The present invention provides a SAR image coherence speckle suppression method. The method uses the probability density function of multiplicative noise and prior information to construct the approximation term, diffusion term and sparse constraints of the model, establishes a sparse partial differential equation model, and Through alternate optimization and solving, the SAR image after coherent speckle suppression can be obtained. The SAR image coherence spot suppression method based on sparse partial differential equations of the present invention can effectively overcome the shortcomings of the traditional filtering method and the partial differential equation method. While suppressing image coherence spots and improving the SAR image radiation resolution, it can well maintain the radar target. Edge information and scattering characteristics can effectively improve the quality of SAR images, and the model can be numerically solved in a robust manner for easy implementation.

Description

technical field [0001] The invention relates to an image processing method, in particular to a SAR image coherent spot suppression method. Background technique [0002] Synthetic aperture radar is a coherent imaging system. When it images distributed targets, the echoes of a large number of scattered points in the same spatial resolution unit have interference phenomenon, which is manifested as coherent speckle noise on the SAR image. Speckle noise not only reduces the radiation resolution of SAR images, but also adversely affects the subsequent applications of SAR images such as edge detection, image segmentation, and object classification. Therefore, speckle suppression is an important part of improving the quality of SAR images. [0003] At present, there are mainly two technical approaches for coherent speckle suppression methods, one is multi-view processing, and the other is filtering processing. Multi-look processing usually reduces the spatial resolution of SAR imag...

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Problems solved by technology

However, since the above partial differential model was first proposed for the additive noise of optical images, it needs to be improved when it is applied to the multiplicative coherent speckle noise of SAR images. The electromagnetic scattering characteristics of optical images vary greatly, and partial differential equations cannot well maintain the scattering characteristics of radar targets

[0005] The sparse partial differential equation method is an improvement of the partial differential equation method, which is used to solve the stable solution of the dynamic equation, and cannot be directly applied to coherent speckle suppression in SAR images

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