Fusion of remote sensing images based on nonsubsampled contourlet transform and region segmentation

Abstract

The purpose of remote sensing images fusion is to produce a fused image that contains more clear, accurate and comprehensive information than any single image. A novel fusion method is proposed in this paper based on nonsubsampled contourlet transform (NSCT) and region segmentation. Firstly, the multispectral image is transformed to intensity-hue-saturation (IHS) system. Secondly, the panchromatic image and the component intensity of the multispectral image are decomposed by NSCT. Then the NSCT coefficients of high and low frequency subbands are fused by different rules, respectively. For the high frequency subbands, the fusion rules are also unalike in the smooth and edge regions. The two regions are segregated in the panchromatic image, and the segmentation is based on particle swarm optimization. Finally, the fusion image can be obtained by performing inverse NSCT and inverse IHS transform. The experimental results are evaluated by both subjective and objective criteria. It is shown that the proposed method can obtain superior results to others. Key words: image fusion, multispectral remote sensing image, panchromatic image, nonsubsampled contourlet transform (NSCT), particle swarm optimization (PSO) CLC number: TP 751.1 Document code: A IntroductionRemote sensing image is an important data source to describe the information of the earth's surface. Given the constraints of remote sensing sensors, there is an inverse relation between the spatial and spectral resolution of images obtained from these sensors. For example, panchromatic (PAN) images of high spatial resolution can provide detailed geometric information, while multispectral (MS) images of low spatial resolution are used to obtain the spectral information. Image fusion technique can take advantage of the complementary spatial/spectral characteristics to produce a fused image with high spatial and spectral resolution simultaneously. The high-quality fused images provide good data source for the further applications such as object detection, recognition, classification and so on.Many image fusion methods have been proposed, including intensity hue saturation (IHS) [1][2] , principal components analysis (PCA) [3] and wavelet transform [4][5][6] . IHS method can enhance spatial features of fused images, but it suffers from spectral distortion. PCA method will lose some original spectral features in the process of principal component substitution. Nowadays, the methods based on multiresolution analysis have become the most promising ones for the image fusion. Wavelet transform method can preserve spectral information efficiently, but wavelet transform is scant of shift-invariance and multidirectionality, which makes it fail to provide an optimal representation for image. Contourlet transform and nonsubsampled contourlet transform (NSCT) overcome the above disadvantages, which have advantages of localization, directionality and anisotropy. In addition, NSCT has shiftinvariance property that contourlet transform lacks of. When NSCT is introduced to image fus...

Comparison of Human Articular Cartilage and Polyvinyl Alcohol Hydrogel as Artificial Cartilage in Microstructure Analysis and Unconfined Compression

“…Moreover, articular cartilage is a kind of dense connective tissue with 70-80wt% water. PVA hydrogel prepared in this work composed about 60% water by weight [20]. The different response of PVA hydrogel and articular cartilage may also relate to the water content.…”

The Dilemma of Mouthpiece: Work Adjustment and Career Decision of News Presenters in Transformation of Chinese Broadcast Media

“…Bureaucracy is a prevalent form of organizational management in modern society, characterized by a strict division of labor and intricate regulations and rules (J. Wu et al, 2018, p. 156).…”

A Novel Fusion Framework Based on Adaptive PCNN in NSCT Domain for Whole-Body PET and CT Images

“…It is known that the fusion result could be improved by making better use of image information. NSCT is a multiscale, multidirectional, and fully shift-invariant transform which could well suppress pseudo-Gibbs phenomena [ 5 , 6 ]. Besides, more information could be obtained by NSCT leading to better fusion performance.…”