**2. Augmented reality technology**

Augmented reality is achieved by providing elements in a scene which can be recognized by computer vision software and tracked over time [3]. Once recognition has been obtained, the coordinates associated with the recognized image, including its orientation in space, then become the anchor point for overlaying 3D virtual reality elements in relation to this anchor point. Often AR involves careful design to ensure that the virtual elements merge seamlessly into the real elements from the observer's perspective, so that it becomes difficult to distinguish what is real from what is virtual. That is the magic of AR, that it provides an enhanced or enriched image of the real world.

The task of creating computer vision software to do the recognition and tracking is a formidable one. Fortunately, a number of APIs now exist that do a lot of the basic work, and instead the programmer can focus more on the interface design and visual integration, which is also a challenging problem. We selected the Vuforia™ API after studying several alternatives [4]. This API is sufficiently mature to support robust work in AR. On the downside, however, it offers few possibilities for adjusting the recognition parameters. In a sense it must be treated as a black box.

In earlier work, we used artificial high contrast patterned targets, such as the one shown in **Figure 1** [5]. Indeed, following numerous studies and trials in the early years of work on AR, these patterned targets had become the de facto standard for ensuring reliable recognition and tracking [3]. However, although these patterns

**Figure 1.** *Example of our initial effort using a printed pattern target.*

*Plenum a la Mode - Augmented Reality Fashions DOI: http://dx.doi.org/10.5772/intechopen.99042*

still provide the best targets, the APIs now support non-standard targets - in fact anything that offers high contrast in an asymmetrical pattern can act as a target. Furthermore, Vuforia offers a cylindrical recognition mode. Essentially, instead of recognizing a flat target, the software will recognize a cylindrical target, which can be tracked even as it turns, thus allowing virtual elements to be added in relation to the cylinder which follow as it turns. For applications involving garments, this is ideal.

We use the Unity Game Engine™ as our programming or interface environment. Unity provides a stable, robust, integrative framework for immersive reality projects, and interfaces directly with Vuforia [4]. We have used it in the past for both virtual reality [6, 7] and augmented reality applications [5].
