M-band wavelet transform for the generation of high-resolution multispectral images

Abstract

This paper introduces an image fusion method, multiresolution analysis-based intensity modulation (MRAIM), which can be used to fuse a high-resolution panchromatic image (HRPI) with low-resolution multispectral images (LRMIs) to yield high-resolution multispectral images (HRMIs). It is designed to solve the fusion case in which the resolution ratio between the LRMIs and the HRMI is an arbitrary integer. It is based on the physical principle of remote sensing image formation, the M-band wavelet transform, and the à trous algorithm. A general image fusion method is derived from the physical principle of image formation, which in turn is based on the simplified radiation transfer model. Using the general image fusion method, it is shown that the pixel values of HRMIs are determined by the pixel values of a low-resolution panchromatic image (LRPI), the approximation of the HRPI at the resolution level of the LRMIs. The M-band wavelet transform-based à trous algorithm is used to compute the LRPI from the corresponding HRPI. The key problem in implementing this approach is constructing the M-band à trous low-pass filter. The underlying mathematical concepts of the M-band wavelet transform, construction of a K-regularity M-band scaling filter, and the à trous algorithm are briefly explained. The performance of the MRAIM method is compared with a state-of-the-art wavelet transform image fusion method, AWRGB, in an experiment using IKONOS panchromatic and multispectral images. It is shown that the MRAIM method can yield a higher quality synthesis of the HRMIs and can be used to generate IKONOS HRMIs.