Focusing on multi-focus image fusion

this paper presents a Curvelet domain method based on grey relation of similarity for visible-light images.In this method

source images are respectively decomposed by multilevel discrete Curvelet transform first.Then

after high frequency coefficients were divided into small blocks

grey Euclid relational degrees of grey theory are used to compute the similarities of these blocks

on which the high-frequency coefficients are fused

while the arithmetic mean method is used to fuse the low-frequency coefficients.Finally

a fused image is reconstructed with the fused coefficients by performing the inverse Curvelet transform.Experimental results show that the proposed method is superior to pyramid-based methods and wavelet-transform-based methods in terms of entropy

standard deviation and clarity.