Multi-focus image fusion based on L1 image transform

Abstract

In this paper, a new multi-focus image fusion algorithm based on L1 image transform is proposed. A distinctive advantage of the proposed algorithm is that an edge-preserving image decomposition (EPID) framework is constructed by introducing a L1-norm based image transform, which can not only effectively preserve and sharpen salient edges and ridges while eliminating insignificant details in the smoothing subband, but also maintain the detail information in the detail subbands. Another advantage is that the fusion rules for the smoothing subband and detail subbands are designed respectively according to their own characteristics so that both the structure and detail information can be fully retained. The fusion process mainly consists of the following three steps. Firstly, each source image is decomposed into a smoothing subband and several detail subbands by utilizing the EPID framework. Then, the subbands are fused by different fusion rules respectively to obtain a fused smoothing subband and a series of fused detail subands. Finally, the final fused image is reconstructed with less distortions by synthesizing the fused smoothing subband and a series of fused detail subands. Experimental results demonstrate the superiority of the proposed algorithm in terms of the visual perception and objective assessments.