多进制小波的遥感影像融合对比分析

Comparison and Analysis of Remote Sensing Image Fusion Using M-Band Wavelet

提出了利用多进制小波进行融合的方案,目标是为了深度挖掘小波在遥感影像像素级融合方面的应用。采用多进制小波进行融合的优势是在减少能量损失的前提下使高频分量的分解方向更加细化,重构时频段组合更加灵活。首先从理论方面阐述了多进制小波和二进制小波(包)的异同,通过对比分析在像素级遥感影像融合实验结果,同时结合目视效果和多种评价指标,发现对于中分辨率——北京一号遥感影像,用多进制(M=4时)db5小波对全色和多光谱遥感影像进行融合的效果不亚于采用二进制小波(包)的融合效果。实验结果表明,小波融合的效果取决于小波基的选取、分解级数,也因处理对象而不同,但在采用相同的小波基的基础上,多进制小波比二进制小波(包)融合效果在目视效果和融合指标两方面都略胜一筹。其为小卫星数据在中国水资源、灾害、考古等领域的重点应用推广的数据处理方面打下基础,同时可为其他不同分辨率遥感影像的类似处理起到示范作用。

To investigate the fusion application based on multi-band wavelet transformation for remote sensing imagery, this paper presents an introduction to m-band wavelet transformation theory and a typical case in image fusion. Meanwhile, results from dyadic wavelet, dyadic wavelet packet and m-band wavelet transformation are compared; and the experimental results from different image fusion schemes are compared, including substitutive, addictive, as well as weighted models. It has been found that, m-band wavelet-based schemes perform better than dyadic schemes. In a word, it is the only scheme, not the best scheme. That is to say, the results from wavelet-based fusion methods can be improved by choosing more appropriate wavelet bases and more sophisticated models for injecting detailed information; however, there is still a long way to go.