Proceedings Article | 23 August 2024
KEYWORDS: Depth of field, Liquids, Liquid lenses, Cameras, Image sharpness, Image processing, Imaging systems, Image segmentation, Zoom lenses, Image fusion
In recent years, increasing the depth of field of optical imaging system has been a research hotspot in the field of applied optics. This is because the optical imaging system with large depth of field can be applied in many fields. For example, it can be applied to machine vision, biological or medical microscopic imaging, optical remote sensing and other fields. However, the hardware structure of the traditional zoom system is complex, the zoom process is cumbersome, and the zoom range is limited. It is difficult to meet the increasingly complex and diverse industrial application requirements. In order to obtain reliable images quickly and efficiently, new zoom imaging methods must be introduced. In this study, a system of increasing depth of field based on image clarity is designed by using liquid lens. The system includes two parts : hardware and control. The hardware part integrates the liquid lens into the optical system, eliminating the use of mechanical devices. It only needs to use the camera, ordinary lens and liquid lens to realize the function of the traditional mechanical zoom device, greatly improving the image acquisition efficiency and imaging quality, and effectively overcoming the limitations of the traditional lens depth of field. The control part mainly consists of three parts : image acquisition, autofocus and image fusion. The system is specially used for large quantities of object detection with height difference. An experimental device was built with a liquid lens, a common lens and a camera used in the laboratory. In the study, a large depth of field imaging method is designed according to the zoom characteristics of the liquid lens. The focus images of different regions are obtained by using the sharpness evaluation function, and the large depth of field image is obtained by fusion. Large depth of field imaging experiments are carried out in different scenes. The results show that the proposed method overcomes the limitation of the depth of field of the lens, effectively expands the depth of field of the lens imaging, and realizes the focused imaging of objects with height difference. It has potential application value in industrial detection, medical diagnosis and many other directions.
