Because the morphological top-hat operator can extract the local optima of an image,this paper applies it to two main fields of multisensor image fusion:multifocus image fusion and panchromatic and multispectral image fusion.In experiments,our methods are compared with the algorithms based on Laplacian pyramid,wavelet transform,and principal component analysis.The results show that our approaches outperform the others,and exploit the application scope of the top-hat operator.