The Research On Superresolution Of Remote Sensing Object Images

Due to resolution limitation of remote sensing images,the accuracy and extent of object recognition for remote sensing images is constrained greatly.The developing of high resolution remote sensing technology is an effective method for this problem,but it will be confronted with more and more difficulty.In this thesis,a new processing scheme of accurate object recognition,detailed object description or object analysis based on the resolution enhancement of remote sensing object images is proposed.The resolution enhancement of remote sensing object image based on superresolution reconstruction algorithm of image sequence is achieved which breaks through the resolution limitation of the remote sensing images and creates favorable conditions for accurate object recognition and further object processing,so this new processing scheme is of great significance both in the military and civil domain. Some key technologies of the resolution enhancement of the object images including the high accuracy registration method of object image sequence,the superresolution reconstruction method of object image sequence,the object image acquisition method and the composing method of object image sequence are studied thoroughly.The superresolution reconstruction algorithm is the core of the resolution enhancement of the object images.The superresolution image acquisition model based on image sensor array is applied to the superresolution reconstruction of image sequence and then a new algorithm of superresolution reconstruction of image sequence based on the DCT Transform and preconditioned conjugate gradient method is proposed.By using the fractional delay filter(FDF),the model of superresolution reconstruction of image sequence is turned into the model of image deblurring and a new algorithm of superresolution reconstruction of image sequence based on FDF and DCT Transform is then proposed.This model change is of great significance because a lot of algorithms of image deblurring can then be applied directly to the image superresoluiton reconstruction.The high accuracy image registration of the object image sequence is the base of the superresolution reconstruction of object images.A high accuracy image registration method for image rotation angle and image resizing factor based on the characteristic spectral line of images is proposed.Combining with the improved shifted image registration method based on the Radon Transform,the new image registration method attains the high accuracy estimation of image shift,image rotation angle and image resizing factor successfully.The function of object shape in the processing scheme of accurate object recognition and further object processing based on the object image resolution enhancement is analysed.The remote sensing object image acquisition method based on PDE method and the object shape is studied and the image enhancement algorithm with complex diffusion based on iterative real edge attributes,the multiple regions image segmentation algorithm combined with the object shape prior are proposed.The method of selecting the object of interest from the database of remote sensing object images to compose the object image sequence is studied and a new method of estimating the object shape distance based on level set is proposed.Then an identity determinant structure based on the object shape distance is designed to ensure all the object images in the sequence belong to the same object.The constitution model of object image sequence is analysed and in order to justify the existing image rotation and resizing accurately before the reconstructing operation,a new image rotation and resizing algorithm with high performance is proposed which is based on B-spline interpolation.Then the simulation method of superresolution reconstruction of object image sequence using the algorithm based on FDF and the DCT Transform is designed,and the expected superresolution result is obtained through a lot of simulation tests and performance analysis.Finally,all research contents are summarized and some important problems which need further study are discussed,such as the method of further improving the algorithm performance and the way to bringing the whole technology of superresolution reconstruction of object image sequence into effect.