SAR image change detecting method based on non-local mean

Abstract

The invention discloses an SAR image change detecting method based on non-local mean filtering. The SAR image change detecting method comprises the steps that two SAR images which are obtained from the same region at different times are pre-processed; the two pre-processed SAR images are used for constructing a ratio difference shadowgraph; all pixels of the ratio difference shadowgraph are traversed and a smooth index matrix of each pixel point is calculated; after non-local mean filtering is conducted on the two pre-processed SAR images respectively, ratio calculation is conducted, and a non-local mean filtering ratio graph is obtained; the ratio difference shadowgraph and the non-local mean filtering ratio graph are summated with smoothness indexes as weights so as to obtain a final difference shadowgraph; the final difference shadowgraph is divided by using the fuzzy local C mean clustering method to obtain a change detecting result graph. According to the SAR image change detecting method based on non-local mean filtering, difference graph edge information is maintained by using the characteristics of the image smoothness indexes, a non-local mean is used for correcting the pixels in a homogeneous region with a low smoothness index, therefore, noise is effectively restrained, actual change information is better shown and the change detecting result accuracy is improved.

Description

technical field [0001] The invention belongs to the field of remote sensing image change detection, and in particular relates to a SAR (Synthetic Aperture Radar, Synthetic Aperture Radar) image change detection method for constructing difference images based on the idea of ​​non-local mean value. Background technique [0002] Synthetic aperture radar (SAR) image change detection is a technology that acquires multi-temporal remote sensing images of the same geographic area at different times, and qualitatively analyzes and determines the process and characteristics of surface changes. Compared with optical imaging, synthetic aperture radar (SAR) has all-weather , the ability to acquire data throughout the day, and the ability to pass through certain vegetation and cover. Compared with optical imaging, it is easier to identify targets on the ground, and it is generally used as a powerful supplement to optical sensors. SAR image change detection technology is being widely used ...

AI Technical Summary

Problems solved by technology

[0006] In view of this, the technical problem to be solved by the present invention is that, aiming at the problem that the quality of the difference map produced by the existing difference map generation method is not high and the information is lost more, a method for constructing a difference image map based on non-local means is proposed for SAR The method of image change detection, according to the characteristics of SAR images, uses the pixel smoothness index as the weight, introduces the idea of ​​non-local mean into the difference image construction process, and constructs a difference image map that contains more effective information and can suppress noise to a certain extent. Improving the Accuracy of SAR Image Change Detection

Images