Webcam clip art
Abstract
Webcams placed all over the world observe and record the visual appearance of a variety of outdoor scenes over long periods of time. The recorded time-lapse image sequences cover a wide range of illumination and weather conditions -- a vast untapped resource for creating visual realism. In this work, we propose to use a large repository of webcams as a "clip art" library from which users may transfer scene appearance (objects, scene backdrops, outdoor illumination) into their own time-lapse sequences or even single photographs. The goal is to combine the recent ideas from data-driven appearance transfer techniques with a general and theoretically-grounded physically-based illumination model. To accomplish this, the paper presents three main research contributions: 1) a new, high-quality outdoor webcam database that has been calibrated radiometrically and geometrically; 2) a novel approach for matching illuminations across different scenes based on the estimation of the properties of natural illuminants (sun, sky, weather and clouds), the camera geometry, and illumination-dependent scene features; 3) a new algorithm for generating physically plausible high dynamic range environment maps for each frame in a webcam sequence.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2009
- Source ID
- 10.1145/1618452.1618477
Entities
People
- Alexei A. Efros
- Jean-françois Lalonde
- Srinivasa G. Narasimhan
Organizations
- Carnegie Mellon University
- Division of Computing and Communication Foundations
- Division of Information and Intelligent Systems
- Office of Naval Research