To improve the contrast of the fused image and preserve the rich and effective information of the source image,an image fusion algorithm based on Finite Discrete Shearlet (FDST) domain is proposed,with consideration of the excellent characteristics of FDST.Firstly,the source image is decomposed by FDST,and a series of high and low frequency subband coefficients are obtained.Then,the low frequency coefficients are selected by using the improved pixel weighting together with the regional spatial frequency;and the fusion method by the regional average gradient contrast is adopted for the selection of high frequency coefficients.Then,the fused image is obtained with the fusion coefficients reconstructed by inverse transform of FDST.The contrast experiment results show that:1) The fusion result of the algorithm is clear,natural and has appropriate contrast for human subjective vision perception;and 2) The objective evaluation quality indexes are improved compared with other fusion algorithms.It is confirmed that our algorithm is superior to other fusion algorithms,which greatly enhances the quality of image fusion.