Fusion of multi-focus images via a Gaussian curvature filter and synthetic focusing degree criterion

The aim of multi-focus image fusion technology is to acquire an image of every scene all focused on the same visual point at different focal settings. To achieve this goal, we propose an improved multi-focus image fusion algorithm based on a Gaussian curvature filter and synthetic focusing degree criterion. First, in order to realize the salient feature extraction, a Gaussian curvature filter is applied to obtain the most sharpness regions. Then we obtain a coarse fusion map by composing a synthetic focusing degree criterion, which is a combination of the spatial frequency and the local variance of image. The coarse fusion map is further processed by morphological filters and median filters to acquire an optimized fusion map. Finally, the fusion image is obtained via a weighted fusion operation. Experimental results demonstrate that our proposed algorithm can be competitive with, or even outperform, many existing fusion methods on both qualitative and quantitative measures. (C) 2018 Optical Society of America