The purpose of imagefusion is to merge complementary information from multisensor data for visual perception,such as surveillance and reconnaissance. The wavelet transform and Mallat fast algorithmare introduced, an image fusion scheme based on the wavelet transform is proposed and thefused image with visible and infrared image is analyzed in this paper. The result showsthat the fused image of the wavelet transform includes all relevant information aboutsensors, the scheme performs better than the Gaussian-Laplacian pyramid-based algorithm.The principle can be used for two images or more, whether the images are in the samespectral band or not.