Comparison of Laplace pyramid and a trous wavelet transformation techniques for fusion of Ikonos images

Abstract

Image fusion is a technique of obtaining high spatial resolution multi-spectral images from low spatial resolution multi-spectral and high spatial resolution panchromatic images. Various techniques exist to perform such fusion. These techniques, however, do not seem to preserve the spectral information content of original multi-spectral image in the fused image. Hence, in this study a recent and efficient technique of fusion based on the Laplace pyramid was attempted and its efficiency was compared with that of the a trous wavelet transformation techniques. Accordingly, a lower resolution multi-spectral image of Ikonos and its high-resolution panchromatic image were fused using the Laplace pyramid and the a trous wavelet transformation fusion technique. The outputs were evaluated using visual comparison, statistical entropy, average gradient and correlation coefficient. Compared with a trous wavelet transformation techniques, the Laplace pyramid technique proved to be a better option since it preserved most of the spectral information content and improved spatial information.