Image merging and data fusion by means of the discrete two-dimensional wavelet transform

A new technique is developed for the merging and data fusion of two images. Two spatially registered images with differing spatial resolutions and color content are merged by combining multiresolution wavelet-decomposition components from each and then reconstructing the merged image by means of the inverse wavelet transform. The wavelet merger can employ a variety of wavelet bases, but in presentation of the concept, simple orthonormal sets—Haar and Daubechies wavelets—are explored. The wavelet technique is compared with the intensity–hue–saturation merging technique by means of multispectral and panchromatic test images. The results of the comparison show the wavelet merger performing better in combining and preserving spectral–spatial information for the test images.