On Semantics-Based Spatial Data Preprocessing:A Case Study in Non-Ortho RS Images Mosaic
A Three-Level Information Architecture containing Syntactic Information,Semantic Information and Pragmatic Information is put forward in Comprehensive Information Theory (CIT).From this point of view,spatial data analysis is in cooperation with semantic information and Spatial Data Preprocessing (SDP) is corresponding to syntactic information.However,in many practical applications,SDP based only on syntactic information can not get a good effect.Semantics-based preprocessing may be an effective scheme.RS images mosaic is a typical SDP where optimal mosaic line extraction is the crux.Lots of researches based on syntactic information are effective just for orthophoto maps.In this paper,an overall optimal mosaic line extraction scheme has been addressed for non-Ortho RS images.It is argued that there is no projection error in the projection datum fitted by Ground Control Points (GCPs),or regional main height surface which can be recognized in medium resolution RS images.Based on above reasons,the method suggests that GCPs collecting for precise geometrical correction should be on the main height surface,as well as the mosaic line extracting for RS images mosaic.Three sheets of CBERS CCD images of Taiyuan are taken as the experimental data.According to the afore-mentioned method,by collecting GCPs in wide riverbeds,all three sheets are rectified to an existing ETM+ mosaic image.And then,the central lines of wide riverbeds in the overlapping areas are extracted as the mosaic line.The experimental result indicates that this method can extract an overall optimal mosaic line and eliminate the visual texture seam-line effectively,even for non-Ortho RS images.It concludes that SDP based on semantic information can play a good role in spatial data applications.
Semantic Information Comprehensive Information Theory (CIT) Spatial Data Preprocessing (SDP) Overall Optimal Mosaic Line Main Height Surface
Daojun Wang Jianhua Gong Ainai Ma
Institute of RS&GIS,Peking University,Beijing,China,100871;Institute of Remote Sensing Applications, Institute of Remote Sensing Applications,Chinese Academy of Sciences,Beijing,China,100101 Institute of RS&GIS,Peking University,Beijing,China,100871
国际会议
第16届国际地理信息科学与技术大会(16th International Conference on GeoInformatics and the Joint Conference)
广州
英文
2008-06-28（万方平台首次上网日期，不代表论文的发表时间）