The Key Technology Research Of Tilt Photogrammetry In Real-time 3D Modeling

With the rapid development of "digital city" construction,as the basic data of geographic information framework,urban three-dimensional model has been paid more and more attention.Although the traditional three-dimensional modeling method in model precision can be well controlled,it can not meet the needs of large-scale rapid construction of urban three-dimensional model.After years of exploration and research,photogrammetry technology with its rapid and efficient data acquisition ability,a wide range of urban three-dimensional modeling make possible.However,due to the acquisition of aerial photography is a vertical image,there is often a feature of occlusion,filming dead ends,which leads to the side of buildings to obtain texture information is not complete,thus affecting the quality of the three-dimensional model.In the basis of photogrammetry technology derived a new method,oblique photogrammetry technology,which is based on multiple cameras mounted on the same aircraft,can collect the image from multiple angles,and the image also gives accurate geographic information,This provides a new method for rapid and efficient construction of three-dimensional model of the city.In this paper,the oblique photogrammetry technique is used as the starting point,research on the method of constructing three-dimensional real model based on oblique photogrammetry technique,and studies,analyzes and summarizes the key technologies such as oblique image matching,three-dimensional modeling process and model repair.The main research contents are as follows:(1)Oblique image matching technology research.Mainly introduced the SIFT algorithm based on scale invariant features and ASIFT algorithm based on scale and affine invariant features,and two kinds of algorithm are applied to the oblique image matching experiment,the matching effect were compared and analyzed.(2)Real three-dimensional modeling method research.Use SWDC-5 to obtain a region of Shanxi oblique images as the experimental data,combined with ContextCapture real three-dimensional modeling software,the three-dimensional modeling of the experimental area is completed,at the same time,the model complexity and geometric precision are evaluated and analyzed.(3)The model results optimization method research.According to the model results of part of the existing building distortion,uneven ground,floating debris and other problems,combined with the DP-Modeler software of Wuhan TianjiHang Company,the objects and areas of the defects in the model results are decorated and replaced.on the basis of above,summarizing a set of model results of optimization method,to achieve the purpose of fine modeling.