ArUCoTUI

Software Toolkit for Prototyping Tangible Interactions on Portable Flat-Panel Displays with OpenCV
Tangible User Interfaces (TUIs) that integrate digital information with physical interaction require specialized hardware and complex calibration, limiting their adoption in portable or mobile display systems. This paper introduces ArUcoTUI, a computer vision (CV) toolkit for prototyping tangible interactions on portable screens, leveraging standard cameras and the OpenCV library. ArUcoTUI uses ArUco fiducial markers to detect physical inputs. The software toolkit offers streamlined calibration, a signal processing pipeline, and a client application that translates tangible input into structured events for use in HCI applications. Using a conventional camera in a top-down setting with a flat-panel display, we demonstrate how this toolkit supports the development of interactive surface TUIs with advanced features, including 3D spatial interaction, multi-device interaction, and actuated tangibles within applications. We describe the software implementation, which utilizes accessible hardware to support the development of these tangible interactions. We provide the results of a preliminary evaluation with users, including design implications and suggestions for future research and development.