Contact angle measurement is an effective way to investigate solid surface properties. The introduction of low-cost digital cameras, as well as software and libraries for image analysis, has made contact angle measurement potentially accessible to every laboratory. In this review, we provide a comparison of the main methods developed to evaluate contact angle from digital images, including the so-called Young-Laplace method, the circle and polynomial fittings, as well as the mask method. All methods have been implemented and compared analyzing virtual and real drop images in an open-source software, Dropen, developed as an app in MATLAB environment. The code enables single image analysis evaluation, for the robust automatic identification of the contact points and contact angle evaluation, with the goal of minimizing user inputs, automatizing the process and facilitating measurements for all users, from less experienced to advanced wetting experts. Dropen and its code are made available at BOA, the Bicocca Open Access public repository, for use and further development.

接触角测量是研究固体表面特性的有效方法。低成本数码相机以及用于图像分析的软件和库的引入，使每个实验室都可以进行接触角测量。在这篇综述中，我们比较了从数字图像评估接触角的主要方法，包括所谓的 Young-Laplace 方法、圆和多项式拟合以及掩码方法。所有方法都已在 MATLAB 环境中作为应用程序开发的开源软件 Dropen 中实现并比较分析虚拟和真实液滴图像。该代码支持单幅图像分析评估，用于可靠地自动识别接触点和接触角评估，目标是最大限度地减少用户输入，自动化流程并促进所有用户的测量，从经验不足到高级润湿专家。Dropen 及其代码在 Bicocca 开放访问公共存储库 BOA 上可用，以供使用和进一步开发。