Multifocus image fusion by combining curvelet and wavelet transform

When an image is captured by CCD device, only the objects at focus plane would appear sharp. A practicable way to get an image with all objects in focus is to fuse images acquired with different focus levels of the scene. In this paper, we propose a multifocus image fusion algorithm based on combination of wavelet and curvelet transform. Although the fused results obtained by wavelet or curvelet transform individually are encouraging, there is still large room for further improvement because wavelets do not represent long edges well while curvelets are challenged with small features. So in the proposed method, these two methods are combined together. Each of the registered images is decomposed using curvelet transform firstly. Then the coefficients are fused using wavelet-based image fusion method. Finally, the fused image is reconstructed by performing the inverse curvelet transform. The experimental results on several images show that the combined fusion algorithm exhibits clear advantages over any individual transform alone.