A new fast fusion algorithm for multi-focus images based on wavelet transform and adaptive block is proposed in this paper. The proposed algorithm is implemented under the framework of wavelet transformation. For the low frequency coefficients

an adaptive block-based fusion technique is applied

where the optimal block size can be calculated by using differential evolution algorithm. Moreover

a pixel-level label map

which can accurately indicate the origin information of each pixel

is obtained by refining the above low-frequency fusion-result. On the other hand

the high frequency fusion task is completed by combining the local wavelet energy based rule with the information offered by the label map. Finally

the fused image is obtained by performing the inverse wavelet transform. Experimental results demonstrate that the performance of the proposed method is comparable with the state-of-the-art methods on both subjective visual perception and objective evaluation criteria. Furthermore

the proposed algorithm can achieve a good balance between improving the fusion quality and reducing the computational cost.