Joint focusing method based on optimal image-distance interval for multi-image-distance imaging system

Abstract

The multi-image-distance imaging system captures multiple images simultaneously with different focused depths, and uses image fusion to obtain an all-in-focus image for extending the depth of field (DoF). However, an image-distance adjustment strategy that takes into account the optimal DoF extension capability and imaging quality remains to be explored. In this paper, we propose a joint focusing method based on the optimal image-distance interval between the three sensors. First, we propose multi-sensor image-distance adjustment control strategies for different scenes. Then, theoretical analyses and calibration experiments of the optimal image-distance interval are conducted for continuous depth scenes. In order to quantitatively evaluate the DoF extension performance of the imaging system, a DoF estimation method based on point spread function measurement is proposed. Additionally, an evaluation metrics for extended DoF imaging based on the range and continuity of DoF is presented. We have developed a multi-image-distance electric focusing imaging system. Imaging experiments are conducted in various scenes to verify the effectiveness of the joint focusing method. The joint focusing method, based on the optimal image-distance interval, provides an image-distance adjustment strategy to achieve high-quality extended DoF imaging for multi-image-distance imaging systems.