在微流体变焦透镜的研究中,准确检测电解小液滴外形随外加电压的变化情况对寻找材料和衡量微流体透镜性能起到了重要作用。同时,待测液滴的形状参数也是描述液体与特定材料之间亲和力和液滴物理特性的重要参数之一。根据最小二乘法原理,设计了基于图像采集与处理的液滴外形检测系统。搭建实验平台,通过摄像物镜和CCD采集处于一定容器中的液滴外形轮廓图像数据,再经过图像滤波、边缘增强、二值化等图像处理技术,最后以数学模型形式描述液滴轮廓边缘曲线,并对边缘曲线数据进行曲线拟合计算液滴与容器边缘的接触角度。
The veracious measurement to the changes of electrolytic drop pressed exterior voltage could make the task of finding proper materials and estimating the character of micro fluid variable-focus lens convenient and fast in the process of the researches on the micro fluid variable-focus lens. Meanwhile, the outline of sessile drop is a vital parameter described the liquid's physical character and the accessibility of a liquid between different liquids or liquid and solid. According to the methods of image processing and the principle of least square method, a system to measure and calculate the outline of a sessile drop based on the technology of image collection and image processing was designed. Building a experiment platform, the sessile drop are captured automatically by camera, then, through edge enhance, binarization, image filtering and edge detection, contour line of a sessile drop is imitated. At last, the contour line is described into a mathematical model and a fitting curve line and contact angle between drop and container are calculated.