The VUI project allows for novel human-computer interaction by using a real-time video stream for gestural user input. The visual field is divided into sensing regions that may or may not be registered with objects or interface representations in the physical environment allowing for scalable arbitrary spatial UIs. One goal is to leverage existing widely-accessible low-cost technologies, such as webcams, to facilitate deployment of application software to end users. Applications include practical context-specific user interfaces, gaming, interactive art installations, and performance art.