Augmented Environments Lab

Abstract

Non-photorealistic rendering (NPR) is an attractive approach for seamlessly blending virtual and physical content in Augmented Reality (AR) applications. Simple NRP techniques, that use information from a single rendered image, have been demonstrated in real-time AR systems. More complex NRP techniques require visual coherence across multiple frames of video, and typical offline algorithms are expensive and/or require global knowledge of the video sequence. To use such techniques in real-time AR, fast algorithms must be developed that do not require information past the currently rendered frame. This paper presents a watercolor-like NPR style for AR applications with some degree of visual coherence.

Watercolor-like AR. Three virtual objects (a teapot, a cube and a bunny) and several real objects (pens, notes, a bottle and a tissue box) are stylized.

Reference
Jiajian Chen, Greg Turk, Blair MacIntyre, Watercolor Inspired Non-Photorealistic Rendering for Augmented Reality, In Proc. ACM Symposium of Virtual Reality Science and Technology (VRST08), October 2008, Bordeaux, Fracne [pdf]

Abstract

Registration errors between the physical world and computer-generated objects are a central problem in Augmented Reality (AR) systems. Some existing AR systems have demonstrated how to dynamically estimate registration errors based on estimates of spatial errors in the system. Using these error estimates, these systems also demonstrated a number of ways of ameliorating the effects of registration error. One central part of this previous work was the creation and use of error regions around objects; unfortunately, the analytic methods used only created accurate regions for simple convex objects. In this paper, we present a simple and stable algorithm for generating the uncertainty regions for complex objects, including non-convex objects and objects with interior holes. We demonstrate how our approach can be used to create a set of more accurate error-based highlights in the presence of registration error, and also be used as a general highlighting mechanism.

Correct boundary for complex objects: a teapot and bunny

Reference

Jiajian Chen, Blair MacIntyre, Uncertainty Boundary for Complex Objects in Augmented Reality, In Proc of IEEE Virtual Reality (VR08), Reno NV, March 2008 [poster]