Research On The Image Fusion In Remote Sensing Technology Based On The Wavelet Transform

As one of the important aspects of image fusion, remote-sensing image fusion (RSIF) investigates how to integrate image information from different aerial remote sensors, and generate new data, which are more complete, objective, and essential cognition for the target. With the development of information technologies, currently, RSIF becomes indispensable in image processing and understanding, along with many important military and civil applications.Wherefore , based on wavelet transform, some important aspects of remote-sensing image fusion is studied in this thesis. This thesis mainly talks about four parts:This paper presented what is remote sensing image, the conception of remote sensing image fusion and the development situation in the national and inter-national. Aiming at the problem which the original image will affect the quality of the fusing image, so this paper gives the image pretreated processes such as: geometry emendation, remove noise and image registration.This paper detailed discusses several classical methods of pixel level as follows : linear average weighting method, highpass filtering fusion method, HIS transform, principle component analysis transform, wavelet transform etc. This paper discuss the effects of the wavelet function and the decomposed level on remote fused image deeply. The research provides basis for choosing wavelet function and the decomposed level. With detail comparison of their characteristics and performances, some conclusions have been drawn: For the fusion of SAR image and TM image, compared with the traditional algorithms, the new algorithm based on wavelet transform retains SAR image's texture and structural information well, and its ability to preserve TM image's spectral information is far better than other algorithms.In four groups based on information quantity, statistic speciality, correlation and gradient respectively, are summarized for fusion evaluation, which are utilized in the experiments to acquire both qualitative and quantitative analysis of the fusion results;This paper discussed some fusion algorithms based on the lifting wavelet transform, and proposed a new fusion algorithm-HIS lifting activity-level fusion algorithm, which gives out very good fusion performance. This scheme makes best use of the information in remote sensing images to be fused and prevents the loss of image information. Through the experiment using SAR image and TM image, all the spectral characteristics, and the spatial quality of image have been improved.