Novel multi-image plumb line track matching method capable of returning multiple elevation values

Abstract

The invention discloses a novel multi-image plumb line track matching method capable of returning multiple elevation values. The method comprises the following steps of: confirming m to-be-matched points of a ground space element (X0, Y0) on a benchmark image by using an image imaging model; matching multiple images restrained by space information to m to-be-matched points; calculating space three-dimensional coordinates (Xi, Yi, Zi) corresponding to the to-be-matched points and an absolute difference (deltaXi and deltaYi) between each coordinate (Xi, Yi) and the space element (X0, Y0) by adopting a multi-image adjustment bundle method, and deciding the returned elevation values according to whether the absolute difference is less than a set threshold. In the multi-image plumb line track matching method, multi-image matching and accuracy test of matching result are together fused to effectively eliminate wrong matching, so that the method can solve the disadvantage that only one elevation value can be returned by the traditional ground image matching method.

Description

technical field [0001] The invention belongs to the fields of digital photogrammetry, geographic information system and computer vision, and relates to the matching constraint strategy, the determination of the search range and the elimination of wrong matching results in the process of multi-view image matching based on object space. Background technique [0002] Digital photogrammetry technology is an important means to extract and update geometric information, radiation information and semantic information of three-dimensional space objects from two-dimensional digital images. It plays an important role in national economic construction and social development, and is widely used in basic surveying and mapping, Land and resources survey and development and digital city modeling and other fields. As a key technology in digital photogrammetry, image matching runs through the entire process of photogrammetry data processing, and has always been a research hotspot in the field...

AI Technical Summary

Problems solved by technology

[0005] However, it is difficult to accurately determine the value of ΔZ in the search process of the existing ground element image matching methods, and it is impossible to guarantee the Z value of the search point. i It must pass through the ground point; if the value of ΔZ is too large, the correct candidate point will be missed; if the value of ΔZ is too small, it will take too much calculation and search time

In addition, the existing method can only return one elevation value at each ground point, which is obviously not necessary for vertical objects with multiple elevation values ​​at the same plane position (such as house facades, utility poles, etc.). to a reasonable reflection of the actual elevation distribution of ground features

Moreover, the existing methods lack sufficient verification process for the accuracy of the matching results, and it is difficult to guarantee the accuracy of the matching results only by the matching similarity of the image square

Images