Multi-focus image fusion by progressive pixel extraction

In recent years, there has been great progress in the field of multi-focus image fusion. However, existing methods still have their respective defects, and the quality of fused image needs to be improved further. In this paper, a novel fusion method by progressive pixel extraction is proposed. In accordance with the sums of all high-frequency coefficients in a series of windows, the method aims at extracting sharp pixels instead of merging transformed coefficients or extracting sub-blocks as used in other methods, and its extraction process is conducted with progressive strategy at continuously increased window size. As a result, artifacts and block effects are largely reduced in the fused image, and the contradiction between precisely extracting clear edges and extracting larger area is resolved. Practical experimental results demonstrate that the proposed method is far superior to the comparable methods in terms of visual effect and objective evaluation.