Research On Building Height Information Extraction Method Based On Shadow Of High-resolution Image In Multiple Scenes

Remote sensing is a technology that acquires target's rich knowledge data through sensors.With the rapid development of urbanization,obtaining information on the height of city buildings is of great significance to the city planning and development.Extracting the height of artificial features from remote sensing images,especially building height,is a hot topic of research in recent years.Based on the analysis of multiple distribution of buildings in the image.This paper combines object-oriented building shadow extraction method and remote sensing image building height extraction method to research the building height extraction method under different scenes.Firstly,the author combined with the distribution of multiple buildings to analyze the shadow of building from the spectral features,geometric features,etc.Then the shape,spatial location,distribution density and other factors of the building were taken into account to classify the distribution of building in multiple images statistically,and the distribution of building in the image was grouped into five different scenarios.Secondly,an object-oriented building shadow extraction method is proposed for high-resolution remote sensing images,which integrates the images characteristic components and the shadow's morphological characteristics of buildings.By analyzing the spectral characteristics of remote sensing images,the first component(PC1),the green band component(G),the excess green(EXG)and the hue characteristic(H)are constructed,then we used the gamma transform to enhance the H band,and normalized the DN value of each characteristic component and make a comprehensive analysis.According to the morphological characteristics of building shadow,established the area and aspect ratio rule and built a rule set to implement object-oriented building shadow information extraction.Experimental results show that the proposed method can not only effectively reduce the influence of water bodies,vegetation and dark objects,but also remove the shadow of non-building structures.Compared with the traditional shadow extraction method based on pixel information,this method can obtain complete building shadow patch but without fragmentation.At last,the paper analyzes the relationship among the shadow of buildings and the elevation angle of the sun,the azimuth of the sun,the elevation angle of the satellite,the azimuth of the satellite,the topography,the shape of the building,and the distribution density of the building,establishes building height calculation models for simple scenes,complex terrain and other scenes.Under the Visual c#.net development environment,the author successfully implemented the extraction of the shadow length of the fishing net method and the removal of gross errors based on ESRI ArcGIS Engine.And comparing the building height extraction results with the field measurement results in multiple scenes to evaluate the accuracy and analyze error of the experimental results.This article began with the different distribution of buildings in the image and setted up a building height extraction model under multiple scenes.The shadow of building was extracted by object-oriented method,and then the building height was extracted by shadow method and rational function method.Comparing with the results of on-site measurements,the results of the extraction showed that the accuracy is relatively high,which verified the accuracy of the proposed method.