Gradient domain guided filter based multi-focus image fusion through focus map extraction and optimization

Abstract

To be an useful image fusion method, multi focus image fusion methods have been widely studied in image visual and detail enhancement. In this paper, a gradient domain guided filter multi focus image fusion method and focus map extraction method is put forward here. Firstly, a new focus map method is put forward based on detail layer decomposed by gradient domain guided filter. Besides, a focus decision map is generated by pixel absolute maximum criterion. Next, the open and close morphological operators are applied to filtering small unconnected regions. Finally, the refined decision map is optimized by the gradient domain guided filter. Experimental results indicate that the new method has strong robustness than other focusing methods. In addition, our fusion method is better than some other state-of- the-art methods no matter in subjective visual effects or objective evaluations.