Abstract

Focus stacking is a computational technique to extend the depth of field through combining multiple images taken at various focus distances. However, in the large aperture case, there are always defects caused by the large blur scale, which, to the best of our knowledge, has not been well studied. In our work, we propose a max-gradient flow-based method to reduce artifacts and obtain a high-quality all-in-focus image by anchored rolling filtering. First, we define a max-gradient flow to describe the gradient propagation in the stack. The points are divided into trivial and source points with this flow. The source points are extracted as true edge points and are utilized as anchors to refine the depth map and the composited all-in-focus image iteratively. The experiments show that our method can effectively suppress the incorrect depth estimations and give a high-quality all-in-focus image.

© 2016 Optical Society of America

Reconstruction of perspective shifts and refocusing of a three-dimensional scene from a multi-focus image stack

Julia R. Alonso, Ariel Fernández, and José A. Ferrari
Appl. Opt. 55(9) 2380-2386 (2016)

Iteratively reconstructing 4D light fields from focal stacks

Xuanwu Yin, Guijin Wang, Wentao Li, and Qingmin Liao
Appl. Opt. 55(30) 8457-8463 (2016)

Fourier domain post-acquisition aperture reshaping from a multi-focus stack

Julia R. Alonso
Appl. Opt. 56(9) D60-D65 (2017)

Multi-focus image fusion based on dictionary learning with rolling guidance filter

Xiang Yan, Hanlin Qin, and Jia Li
J. Opt. Soc. Am. A 34(3) 432-440 (2017)

Multi-focus image fusion using a guided-filter-based difference image

Xiang Yan, Hanlin Qin, Jia Li, Huixin Zhou, and Tingwu Yang
Appl. Opt. 55(9) 2230-2239 (2016)