An SAR image change detection method based on difference image fusion and an improved level set

Abstract

The invention discloses an SAR (Synthetic Aperture Radar) image change detection method based on difference image fusion and an improved level set, which comprises the following steps: firstly, respectively carrying out logarithmic ratio operation and mean ratio operation on SAR images at two moments to obtain a logarithmic ratio image and a mean ratio image, and then fusing the logarithmic ratioimage and the mean ratio image to obtain a fusion difference image; Carrying out pre-classification on the fusion difference image by utilizing a KI threshold value to obtain an initial mark field anda mean value and a variance of the two types of data sets; According to the initial mark field and the mean value and variance of the two types of data sets, calculating the membership degree of eachpixel point on the fusion difference graph belonging to a certain type, and then constructing a self-adaptive kernel function; Controlling curve evolution of a level set function by combining a global energy item and a local energy item according to the kernel function and gradient information of the image; And finally, dividing a change region and an unchanged region according to a curve duringconvergence. The SAR image change detection method not only protects detail information such as edges, but also effectively inhibits speckle noise, thereby improving SAR image change detection precision.

Description

technical field [0001] The invention belongs to the field of image processing, mainly solves the problem of detection of synthetic aperture radar (Synthetic Aperture Radar, SAR) image change, and specifically provides a SAR image change detection method based on difference map fusion and improved level set. Background technique [0002] SAR image change detection is to compare and analyze two SAR images in the same area in different periods, and obtain the change information of ground objects or targets within a period of time according to the difference between the two images. Because SAR has the advantages of large-scale imaging, no weather influence, and all-weather and all-weather reconnaissance, SAR image change detection technology is widely used in urban planning, land monitoring, battlefield information perception and other fields. Its broad application scenarios make more and more More and more domestic and foreign scholars are committed to developing high-precision...

AI Technical Summary

Problems solved by technology

The threshold method is to find out the optimal threshold for dividing the two categories through a certain threshold selection method. Among them, the scholar Bazi et al. proposed to use the KI (Kittler&Illingworth) threshold to analyze the difference map. This kind of analysis method has low computational complexity and simple method, but There are problems such as low detection accuracy; the level set method is to construct a three-dimensional level set function, and then solve the function value of zero points to form a curve, so as to obtain the result of image classification. Scholars Chan et al. proposed a region-based CV model, which has a good edge detection ability, but because the difference map is susceptible to noise, it is easy to generate messy noise in the region or on the boundary

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