@article{bai2015quadtree,
  title={Quadtree-based multi-focus image fusion using a weighted focus-measure},
  author={Bai, Xiangzhi and Zhang, Yu and Zhou, Fugen and Xue, Bindang},
  journal={Information Fusion},
  volume={22},
  pages={105--118},
  year={2015},
  publisher={Elsevier}
}