Non-Photorealistic Computer Graphics Library

A Pointillism Style for the Non-Photorealistic Display of Augmented Reality Scenes

Author(s): Jan Fischer, Dirk Bartz.
Technical Report: Wilhelm Schickard Institute for Computer Science, University of Tübingen, No. WSI-2005-05, May, 2005.
[BibTeX]

Abstract:
The ultimate goal of augmented reality is to provide the user with a view of the surroundings enriched by virtual objects. Practically all augmented reality systems rely on standard real-time rendering methods for generating the images of virtual scene elements. Although such conventional computer graphics algorithms are fast, they often fail to produce sufficiently realistic renderings. The use of simple lighting and shading methods, as well as the lack of knowledge about actual lighting conditions in the real surroundings, cause virtual objects to appear artificial. We have recently proposed a novel approach for generating augmented reality images. Our method is based on the idea of applying stylization techniques for reducing the visual realism of both the camera image and the virtual graphical objects. Special non-photorealistic image filters are applied to the camera video stream. The virtual scene elements are rendered using non-photorealistic rendering methods. Since both the camera image and the virtual objects are stylized in a corresponding way, they appear very similar. As a result, graphical objects can become indistinguishable from the real surroundings. Here, we present a new method for the stylization of augmented reality images. This approach generates a painterly "brush stroke" rendering. The resulting stylized augmented reality video frames look similar to paintings created in the "pointillism" style. We describe the implementation of the camera image filter and the non-photorealistic renderer for virtual objects. These components have been newly designed or adapted for this purpose. They are fast enough for generating augmented reality images in real-time and are customizable. The results obtained using our approach are very promising and show that it improves immersion in augmented reality.