A novel image fusion algorithm based on IHS and discrete wavelet transform

As an important part of image fusion algorithms, pixel-level image fusion can combine spectral information of coarse resolution imagery with finer spatial resolution imagery. The objective of this paper is to propose a novel pixel-level multisensor image fusion algorithm combining intensity-hue-saturation (IHS) transformation and discrete wavelet transform (DWT). A new fusion rule based on local energy feature and local average gradient feature is developed for appropriately combining the wavelet detail coefficients of the intensity component and the original high spatial resolution image with an operation of amplification on the wavelet detail coefficients of the original high spatial resolution image. The proposed method was compared visually and qualitatively with existing standard HIS transformation and standard DWT strategies. Experimental results presented on a set of multispectral (MS) images and a Systeme Pour I'Observation de la Terre (SPOT) Panchromatic (PAN) image of the same scene indicate that the proposed algorithm performs effectively with respect to those methods in preserving spectral information and improving spatial resolution for the test images.