Active contour synthetic aperture radar (SAR) image segmentation method based on Fisher distribution

Abstract

The invention discloses an active contour synthetic aperture radar (SAR) image segmentation method based on Fisher distribution, which mainly aims to overcome the disadvantage of existing Gamma distribution to the SAR image segmentation technology, the method comprises the following specific implementation steps of (1) making use of Fisher distribution to fit the intensity statistical characteristics of an image area, and establishing an energy functional function based on the Fisher distribution according to a regional competition model; (2) introducing a level set function, and combining a length constraint item and a level set rule item to re-express the energy functional function obtained in step 1; (3) minimizing the energy functional function obtained in step 2 by adopting Euler-Lagrange calculus of variations, estimating Fisher distributed parameters by making use of logarithmic moment estimation, and then performing numerical solution to a partial differential equation, thereby obtaining the segmentation result of an SAR image. According to the method provided by the invention, the level set method evolutionary split curve and Fisher distributed parameter estimation are combined to minimize the energy functional function, thereby realizing segmenting SAR images.

Description

technical field [0001] The invention belongs to the field of image processing, and relates to radar remote sensing application technology, and more specifically relates to a level set segmentation method of a synthetic aperture radar (Synthetic Aperture Radar, SAR) image. technical background [0002] Synthetic Aperture Radar (SAR) is an active sensor that uses microwaves for perception. Unlike optical sensors that rely on light sources, the SAR system is completely active acquisition, not subject to weather, light and other conditions, which makes SAR images better day and night and seasonal stability, and its all-weather, all-day visual ability , these advantages have become an indispensable earth observation technology in military, agricultural, urban planning and other application fields. With the continuous development of SAR equipment and imaging technology, the intelligent interpretation technology of SAR images is facing new challenges. As a key step in SAR image in...

AI Technical Summary

Problems solved by technology

Although the Gamma distribution can better describe the uniform area SAR image data in the case of medium and low resolution, as the resolution increases, the coherent spots of the SAR image are not fully developed, and the uniformity decreases, and the Gamma distribution generally cannot describe it well. Therefore, the current method based on Gamma distribution cannot be used for segmentation processing of high-resolution SAR images.

Second, the existing level set SAR image segmentation methods generally use the signed distance function to represent the level set function, which often requires time-consuming reinitialization steps during the curve evolution process, making the segmentation speed slow

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