Fast and accurate autofocusing algorithm in digital holography based on particle swarm optimization

Numerical autofocusing is one of the key features of digital holographic imaging modality. The conventional procedure of hologram reconstruction at different reconstruction distances followed by the focal plane detection based on a specific image quality metric is usually time consuming. We propose a fast and accurate autofocusing algorithm based on particle swarm optimization technique. Instead of reconstructing hologram at a large number of equidistant positions within the measurement volume, reconstructions are performed at a few random positions, considered as particles, which are updated in an iterative manner. This approach results in significant improvement in the accuracy and computational efficiency of the autofocusing procedure. Simulation and experimental results are provided to demonstrate the applicability of the proposed method. •Fast and accurate autofocusing algorithm in digital holography is proposed.•Conventional autofocusing algorithms are assisted with particle swarm optimization.•The proposed algorithm performance is insensitive to focus search space range.•The proposed algorithm improves the focal plane detection accuracy and computational efficiency.