Method for registering synthetic aperture radar image with change area based on point pair constraint and Delaunay

Abstract

The present invention discloses a method for registering synthetic aperture radar image with a change area based on a point pair constraint and Delaunay, and the problem of SAR image registration with a change area without using ground control point data is mainly solved. The method comprises a step of filtering inputted floating image and reference image respectively and then using a SURF algorithm to extract feature points, a step of carrying out similarity measure matching of a normalized descriptor matrix on obtained reference image feature point and floating image feature point and then carrying out distance and wiring direction angle constraint to obtain an initial candidate matching point pair set, a step of using matching feature points in the floating image and the reference image to construct Delaunay, searching a homonymous triangle pairs in the Delaunay of the two images to update the candidate matching point pair set, and taking non-repeated vertices in all homonymous triangle pairs corresponding to a minimum affine error as a final matching point pair set, and calculating an affine change matrix, carrying out affine conversion and bicubic interpolation on the floating image, and obtaining a final registration result image.

Description

technical field [0001] The invention belongs to the technical field of image processing, and relates to image registration, in particular to a synthetic aperture radar image registration method based on point-pair constraints and a triangular network with changing regions, which can be used for change detection, fusion, splicing, etc. of SAR images pre-registration work. Background technique [0002] Synthetic Aperture Radar (SAR) technology has important applications in military and environmental monitoring due to its good recognition of targets, high resolution, all-weather, and all-time. Before splicing, fusion, change detection and other operations on SAR images, it is necessary to spatially register images from the same region, at different viewpoints at the same time or at different times of the same sensor to eliminate the time, angle, and The difference in environment and sensor imaging mechanism causes problems such as translation, rotation, stretching and local de...

AI Technical Summary

Problems solved by technology

[0017] In 2013, Al-Ruzouq et al pointed out in the literature "Multiple source imagery and linear features for detection of urban expansion in Aqaba City, Jordan" (International Journal of Remote Sensing, v33, n8, pp.2563-2581, April 2012) that the existing The feature-based approach has shortcomings: (1) the proposed similarity metric for matching primitives is empirically based and sometimes subjective; (2) the included imaging must be approximately registered prior to automatic registration

[0018] It can be seen from the above that the registration method of remote sensing images in changing areas that do not use ground control point data generally matches by selecting geometric features of the image such as edges, line segments, contours, etc., and then uses singular points with certain characteristics as control points. Points, the positioning accuracy is often not high, and sometimes it is impossible to find a suitable matching template when dealing with image pairs with large changing areas; and directly extract feature points on the image for matching through correlation operators, such as Harris, SUSAN, etc. Points, SIFT, SURF and other affine invariant feature points are generally based on certain empirical assumptions, sometimes there are many feature points, it is difficult to find suitable matching points as control points

Images