Image fusion using multi-decomposition levels of discrete wavelet transform

Many researchers are concerning with using powerful image processing tools to achieve high quality images for their applications. Recently, great interest has been arisen on using wavelet transforms to analyse multi-resolution images and to fuse remote sensing images. Image fusion, especially in remote sensing applications, is one of the fields that is growing continuously. Many methods have been proposed to fuse panchromatic and multi-spectral images. This work presents a proposed scheme to fuse the Landsat-7 low-resolution (30 m) multi-spectral images and its high-resolution (15 m) panchromatic images. The proposed image fusion method is based on a two dimensional discrete wavelet transform (2D-DWT). The method aims to fuse two images in order to produce a high resolution (15 m) multi-spectral image. It also presents a comparison between the implemented 2D-DWT method and other conventional methods of image fusion using the correlation between the output image and the two input images to ascertain the best possible technique that can result in better results of multi-sensor image fusion. The output image of the 2D-DWT technique contains 86.6% of spectral content of the multi-spectral image and 97.08% of the spatial content of panchromatic image.