An image-based framework for animated non-photorealistic rendering.

摘要

This thesis presents an image-based rendering framework for creating non-photorealistic applications that achieve frame-to-frame coherence, interactivity, stylistic flexibility, and visual detail. To date, most researchers pursuing dynamic non-photorealism have focused on rendering specific visual styles, with methods for achieving frame-to-frame coherence within a particular style being key technical contributions. While such research is an important initial step, systems intended solely to render in a single aesthetic style are too limited to be generally useful, stand-alone applications. Our goal is to create applications in which animated, non-photorealistic imagery is utilized to achieve goals beyond simply rendering.; Successful applications utilizing animated, non-photorealism need to address four key challenges. The first challenge, attaining frame-to-frame coherence, has been the traditional focus of research efforts, and it remains a crucial component of any visually appealing non-photorealistic animation. The second challenge is that many types of applications are inherently interactive and therefore demand interactive frame rates, a significant technical hurdle for non-photorealistic rendering. Third, applications utilizing animated, non-photorealism benefit from stylistic flexibility. Users should be able to experiment with different visual styles to meet aesthetic requirements or individual preferences. Finally, applications should minimize the effort required to achieve rich final imagery containing the necessary, application-specific visual details.; Our framework for meeting these challenges starts with a collection of images (such as photographs, video, or hand-drawn artwork), and then, as an off-line pre-process, constructs a non-photorealistic, image-based representation from this input imagery. After creating this non-photorealistic image-based model, we can use it to interactively synthesize non-photorealistic imagery for display during the run-time application.; We demonstrate the benefits of this image-based rendering framework in three applications: a performance-driven animation system, interactive architectural walkthroughs, and a system for applying non-photorealistic effects to video.