This chapter presents the development of a new human-machine interface - a wheelchair controlled by the recognition of human hands' static gestures. The application will allow the occupant of an intelligent wheelchair to communicate with certain objects in order to facilitate their daily life. The suggested methodology draws on the use of computational processes and low-cost hardware. The development of the application involved dealing with computer vision issues in a comprehensive way. It was based on the steps of video image capture, image segmentation, feature extraction, pattern recognition and classification. In terms of its relevance and impact, the application described in the chapter promotes a more natural and intuitive mode of interaction for disabled individuals, which is expected to improve their quality of life.
TopThe Starting Point: Natural User Interfaces
Natural User Interfaces (NUI) can be considered as any technology that allows a user to interact more intuitively and directly with machines and their information. This new technological generation uses new methods of data entry, such as multi-touch, voice, pen, finger, tracking motion or fiducial markers. This implies a new philosophy of interaction with devices (Blake, 2010). We can therefore conceive NUI to interact with the environment through devices that may be embedded in houses appliances, or even in our clothes.
Natural user interfaces aim to open opportunities for fundamental natural interactions with the user, rejecting mechanical devices to access information. The first developments of NUI date back to 1991, when Mark Weiser presented his vision around two fundamental concepts that still guide the scientific research in the area of Human-machine interface. The first concept is ubiquitous computing mainly covering the hardware (Weiser, 1991). The aim was to make the human-computer interaction so natural that it could integrate the informatics with individuals’ natural actions and behaviors. The second concept was related to the “calm technology” where Weiser pondered about a technology to design the interaction based on calm and comfort, giving primacy to the relationship between the user and the content (Weiser & Brown, 1995).
Natural interfaces are the logical step to achieve this form of interaction, where the user interacts with the computer, using speech, gestures, voice, or even eye movement. For Monson-Haefel (2010) the term NUI is defined as an interface that models the aspects of direct interactions between people and their natural environment. The same term is defined by Blake (2010) as a user interface, designed to use natural human behaviors, to interact directly with the content. However, the easiest way to understand the NUI is to compare it with other more traditional types of interfaces, such as graphical user interfaces (GUI) and interfaces for command line (CLI).