Marcel Würsch

SDK Reinvented: Document Image Analysis Methods as RESTful Web Services

Document Image Analysis (DIA) systems become ever more advanced, but also more complex -- computationally, and logically. This increases the difficulty of integrating existing state-of-the-art approaches into new research or into practical workflows. The current approach to sharing software is publishing source code -- leaving the burden to the integrator -- or creating a Software Development Kit (SDK) which is often restricted to one programming language. We present DIVAServices a framework for sharing and accessing DIA methods within the research community and beyond. Using a RESTful web service architecture we provide access to the methods, leading to only one system on which the binaries of methods need to be maintained. All it takes for a developer to use an algorithm is a simple HTTP request with the image data and parameters for the method and they will receive the computed results in a format that allows for seamless integration into any kind of workflow or for further processing. Furthermore, DIVAServices is open-source, enabling other research groups or libraries to host their own instance in their environment. Using this framework, future DIA systems can be built on the shoulders of well tested algorithms, accessible to everyone.

DivaServices—A RESTful web service for Document Image Analysis methods

In this article we present a web service framework providing automatic document processing methods to the public. Furthermore, an assessment environment and sample applications using this framework are briefly described. Research on Document Image Analysis (DIA) focuses mainly on developing and refining automatic processing steps, e.g. text line extraction, binarization, and layout analysis. While many state-of-the-art methods perform satisfactorily, the algorithms applied to obtain the results are not easily accessible for other researchers. Making the source code available is often not sufficient as it typically requires a cumbersome installation of required libraries and reading long manuals about the usage. We present a new approach for making methods available to researchers in the digital humanities without detailed knowledge of the algorithms. For our approach we propose a RESTful web service architecture, the current state of the art in online web communication. For a developer this reduces the steps needed to access a method to sending and receiving HTTP requests with Java Script Object Notification data, removing all installation steps. We will build on standards such as the Text Encoding Initiative and the International Image Interoperability Framework. Thus, methods hosted on DivaServices can be integrated easily into document processing workflows by any software engineer in computer science, but also the digital humanities without specific knowledge of the mathematical and algorithmic details of DIA.