PCA and wavelet transform for fusing panchromatic and multi-spectral images

Facing the increasing availability of remote sensing imagery, the compression of information and the combining of multi-spectral and multi-sensor image data are becoming of greater importance. This paper presents a new image fusion scheme based on PCA and multi-resolution analysis of wavelet theory for fusing high-resolution panchromatic and multi-spectral images. It is done in two ways: a). By replacing some wavelet coefficients of k-principal components by the corresponding coefficients of the high-resolution panchromatic image; b). By adding the wavelet coefficients of the high-resolution panchromatic image directly to k-principal components. The proposal approach is used to fuse the SPOT panchromatic and Landsat (TM) multi-spectral images. Experimental results demonstrate that the proposal approach can not only preserve all the spectral characteristics of the multi-spectral images, but can also improve their definition and spatial quality. Compared with the PCA fusion method, the proposal scheme is much better and possesses more capable of adaptability.