Research On Automatic Extraction Of Multi-view Aerial Oblique Images DSM Based On Multi-stereo SGM

Multi-view aerial oblique image can obtain the texture information of the building surface and the building facade,and it has important application value in the three-dimensional reconstruction of the building.Because of the large geometric distortion and radiation distortion between the images,the parallax fault and the occlusion of the objects are very serious,which increases the difficulty of extracting the DSM-Digital Surface Model automatically from the images.In this paper,based on the Aerial oblique image DSM extraction technology and the analysis of the characteristics of the tilt image,this paper studies the techniques such as fusion affine complementary invariant feature,oblique image high precision robust matching algorithm,multi-stereo whole matching SGM(Semi-Global Matching)dense matching technology.This paper proposed to automatically match the DSM program,and have made some progress.The major work and achievements are given as follows:1.Depth analysis of AMC580 and other tilting camera imaging characteristics,combined with DSM extraction program.The image preprocessing work,such as image denoising,image enhancement,camera distortion correction and epipolar image generation,is realized by using the experimental data,which provides high quality image for the subsequent extraction of DSM.2.The existing feature detection algorithms are summarized and the complementarity between affine invariant features is studied,and a method of affine invariant feature fusion is proposed.The results show that the feature extraction method can obtain the matching point with uniform distribution and high precision,and improve the reliability of the aerial tilt image feature extraction.It is a good way to extract the aerial tilt image DSM.3.Aiming at the problem that the aerial oblique image matching is difficult to obtain a sufficient number of high and high precision matching points,a high precision matching method based on local approximation plane is proposed.Based on the matching point sparse region encryption strategy and multi-degree overlap matching Point extraction strategy.The results show that the scheme can obtain the matching points with high number,uniform distribution,high precision and multi-degree overlap,which provides a reliable basis for multi-stereo semi-global matching.4.Based on the combination of multi-stereo matching algorithm,SGM algorithm and step-by-step DSM automatic extraction strategy,a DSM automatic method based on multi-stereo SGM dense matching method is designed on the basis of the basic principle of SGM andmulti-view stereo matching algorithm.The experimental results show that the scheme can realize the automatic extraction and fusion of the DSM of the aerial tilt image,and the DSM with high precision can be obtained.