Aerial Photo Processing And Algorithm Design On Allocating Texture Research

Allocating texture is a new texture matching method, compared with the traditional texture mapping,it is a characteristics of speediness and high degree of automation,and it is a kind of texture matching after obtaining the texture of aerial photo, during the study ,it involved in aerial photography survey, three-dimensional modeling, 3D-GIS, computer graphics, digital image processing and other related knowledge of multi-subject, it is interdisciplinary and can be realized by using multi-method,it is a exploring research that is put forward currently on the background of rapid construction of digital city.Allocating texture mainly contains two contents: one is obtaining texture, the other is a matching texture, the former includes reading, writing,cutting and rectifying aerial photo, the latter mainly includes selecting aerial photo and texture mapping.At present,reading spatial data is not a technical problem, and there has been matured technology on texture mapping,thus ,the key point of allocating texture research turns to processing aerial photo and algorithm of selecting aerial photo , based on the above ,the research is carried out,and all the functions of processing aerial photo have been realized.Through aerial photo processing and algorithm selecting, summarized as follows:First,select Visual C + + as a programming environment, because C + + language has good flexibility, we can customize any functions we need.We must establish a processing DIB class because MFC encapsulates nothing about operation of DIB,during reading,writing and cutting the aerial photo,the handle is the main operating object, it is closely related to reading,writing,rectification and showing.Secondly, the affine transformation is an important transformation of obtaining ortho- texture, in the study, differential rectification method was adopted,and it needs to use the least square adjustment method. The affine transformation is of the greatest importance in course of processing aerial photo, and it is an important method that alters the texture's projection relationship from center projection to ortho-projection.In the processing, the indirect method was used,that is,filling blank target rectangle with pixels that corresponds with aerial photo's.Thirdly,there are some questions during allocating texture, which are based on spatial relationship and hard to deal with. To sum up, two main issues, one is the issue of shelter, the other is the best selection of aerial photos. In the study,we designed the algorithms for both problems, however, the robustness and time complexity of these algorithms need to be further verified in practice.At last, the definition of texture is inferior than the traditional method of taking pictures,but fast and automatic is its merit.Texture rectification adopts bilinear interpolation,this method keeps pixels continuous and good results while zooming in or zooming out.