1179
THE FUSION OF SPOT PANCHROMATIC AND TM MULITSPECTRAL
IMAGE BASED ON MULTI-BAND BIORTHOGONAL WAVELET
LIANG Shouzhen 3 ’ b ’ 1 *, LI Lanyong 3
3 School of Geomatics, Liaoning Technical university , Fuxin - Lilanyong@sohu.com 1
b Yantai Institute of Coastal Zone Research for Sustainable Development, Yantai - Liangshzh0816@163.com
Comission VII,WG VII/6
KEY WORDS: Fusion, Multi-band,Biorthogonal,Wavelet,TM,SPOT
ABSTRACT:
Remote sensing image fusion aims at integrating the information conveyed by data acquired with different spatial and spectral
resolution from satellite and aerial platforms. Image fusion is a very important issue in remote sensing and mapping applications
such as features extraction, image classification because the fused image can provide more comprehensive information than single
image. At present there are various methods developed to fuse or merge images from different sources, acquired at different time or
having different characteristics, particularly low-resolution multi-spectral and high-resolution panchromatic images. Some fusion
techniques or methods, such as PCAfprinciple component analysis), IHS (Intensity-Hue-Saturation) and Brovey transform ,can
provide superior visual high resolution multi-spectral images but ignore the requirement of high quality synthesis of spectral
information .In other words, there are some distortion of spectral characteristics in comparison with original multi-spectral
images.This paper develop a nesw method which integrate multi-band wavelet and biorthogonal wavelt to merge remote sensing
images. Multi-band wavelet transform can deal with arbitrary integer ratio of images resolution, while biorthogonal wavelet
transform can reduce the ambiguity on the edge of image because it is symmetric and smooth. A example of fusion based on three-
band and biorthogonal wavelet transform is experimented with SPOT panchromatic image and Landsat TM image and the fused
image is compared with fused images based on orthogonal wavelet ,PCA,HIS and Brovey transform respectively in this paper. Some
parameters including mean gradient, combination entropy, standard deviation and correlation coefficient are adopted to appraise the
fused images.
1. INTRUDUCTION
Image fusion refers to a process that extracts redundant and
complementary information from a set of input images and
fuses it into a single and more complete image. The fused
image should have more useful information content. The fusion
of the two images can take place at the signal, pixel, or feature
level. Presently many image fusion methods have been
proposed for combining remote sensing data .A detailed review
on this issue was given by Pohl and Van Genderen (Pohl et
al, 1998).The well-known methods are, for example, the HIS
(Intensity, Hue, Saturation) (Edwards et al, 1994), PCA
(Principal components Analysis) (Zhou, 1998; Chavez, 1989),
Brovey Transform (Gillespie et al, 1987) .These methods are
conventional methods which have been studied widely. But
these fusion methods have some deficiencies. At least in
comparison with the ideal output of the fusion,these fusion
techniques can often produce poor results.The most obvious
problem is that it leads to some distortion of spectral
characteristics. Recently developments in wavelet analysis
provide a potential solution to these drawbacks. For example,
Nunez developed an approach to fuse a high-resolution
panchromatic image with a low-resolution multi-spectral image
based on wavelet decomposition (Nunez et al, 1999). Ranchin
and Wald designed the ARSIS concept for fusing high spatial
and spectral resolution images based on the multi-resolution
analysis of two-band wavelet transformation (Ranchin et
al,2000).
However, the fusion method based on well-known two-band
wavelet, which have been successful for the fusion of SPOT
panchromatic and other multispectral images, is not very
efficient for the fusion of images whose ratio of spatial
resolutions is not 2 n (n = 1, 2, 3, ...), e.g., for fusing a 10-m
resolution
panchromatic SPOT image and with 30-m resolution
multispectral TM images .Moreover, the two-band orthogonal
wavelet lacks symmetry ,which makes the color of fused image
not been smoothly integrated into the spatial features.Namely it
produces some distortion of spectral characteristics in the
original multispectral images.But biorthogonal wavelet is
symmetric and multi-band wavelet can effectively fuse diffent
ratio of spatial resolution .So these problems can be solved if
integrating multi-band wavelet with biorthogonal wavelet to
fuse remotely sensed data. So in this paper, we adopt the new
fusion technique to merge SPOT panchromatic images with
multispectral TM images.This technique can effectively fuse
differet or arbitrary ratio of spatial resolution such as 30m-
resolution TM images and 1 Om-resolution SPOT panchromatic
images ,and in this approach the color distortion can be reduced
to a certain extent.
The structure of this paper is as follows. The first section is
introduction .In this section mainly introduce the study and
development on image fusion and the structure of the whole
* Corresponding author :Liang Shouzhen, E-mail:,liangshzh0816@163.com