Improved Fusion Method for Remote Sensing Imagery Using NSCT and Extend IHS

Abstract

This paper proposes a hybrid fusion method that can combine the advantages of two popular image fusion schemes: fusion in the spatial domain and fusion in the transform domain. The Extend IHS (EIHS) fusion method is chosen within the spatial domain fusion scheme because this method can well maintain the spatial details of the panchromatic image while reducing the spectral distortion of the multispectral images by taking into account the spectral response of each spectral band. However, using EIHS may lead to severe spectral distortion in some cases as we will discover in this paper, hence Nonsubsampled Contourlet Transform (NSCT) is introduced as it can preserve the spectrum discontinuity of multispectral images. By doing so, both spatial details in the panchromatic image and spectral information in the multispectral image are kept in the fused image. Experiments with QuickBird and IKONOS satellite images show that the proposed method can obtain better visual fusion results than traditional image fusion methods, which is also supported by the image fusion numerical criteria.