We present a new fusion algorithm using a novel multidecomposition approach based on a DFT/RDFT-based symmetric, zero-phase, nonoverlapping digital filter bank representation. For the panchromatic image and each band of the multispectral image, the lowpass and highpass subband components are obtained in a tree structure using zero-phase filters implemented by the RDFT. The approximation subband of the multispectral image is merged with the detail subbands of the panchromatic image. The fused data is recovered from the subband signals by a new perfect reconstruction algorithm. This process is performed on each band of the multispectral image to obtain the final fused high resolution multispectral image.