Body-Centric Projections: Spatial projections relative to the body for map navigation

Doctoral thesis, 2016

Technological advancement has led to the steady improvement of brightness and decrease in size of pico projectors. These small devices are available as stand-alone projectors for personal use or are embedded in consumer electronics, ranging from smart phones, smart glasses, to video cameras. Portable projected displays provide opportunities in creating feasible, desirable, and viable wearable devices that present information. The main contribution of this thesis is to develop and evaluate a set of working prototypes that present information in new ways around the human body for the task of map navigation. Based on experiments using these prototypes, we gain insights and present a design space for mobile visual interfaces from a body-centric human-computer interaction perspective. First, we design interfaces for an architectural application involving environment projection and explore reconstruction of physical surfaces in different contexts. Environment-centric projection is employed to create interfaces in which the user is performing tasks inside a limited physical space augmented with information. Second, we explore the placement of information around the human body while cycling and walking for the task of map navigation in an urban environment. We evaluate these body-centric interfaces through field experiments. Findings from our experiments show that, for instance, while cycling road projection is considered safer and easier to use than a mobile phone, a head-up display is considered safer than a projected display on the road. The implications of display placement could inform the design of visual interfaces for bike design, such as bike sharing systems that are already supporting map navigation using tablets mounted under handlebars. Furthermore, projections on the road could replace headlights to make people more aware of moving vehicles, showing drivers' intentions and the subsequent position of vehicles. Then, we propose the concept of a "wearable mid-air display", a device that presents dynamic images floating in mid-air relative to a mobile user. Such devices may enable new input and output modalities compared to current mobile devices, and seamlessly offer information on the go. A functional prototype was developed for the purpose of understanding these modalities in more detail, including suitable applications and device placement. Experiment results investigate the use of a wearable mid-air display for map navigation.