Focusing algorithm based on droplet measurement

Abstract

In-line digital hologram can realize particle detection in space of 3D coordinate. The in-line digital hologram is based on the coherent light imaging theory. When the distance of reconstruction deviate from the focus, we find the edge of the reconstructed image will appear a lot of stripes caused by diffraction. The traditional evaluation method is to focus on the image directly. It will not be able to get the correct position, and can't get accurate particle three-dimensional of space. In this paper, it is based on the detection of laboratory cloud droplets particles to research the focus plane position of reconstructed image.