Paper Info
Title
Webcam clip art: appearance and illuminant transfer from time-lapse sequences
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.
Year
DOI
Venue
2009
10.1145/1661412.1618477
ACM Trans. Graph.
Keywords
Field
DocType
image based lighting,computer vision
Clip art,Computer vision,Computer graphics (images),Computer science,Image-based lighting,Sky,Standard illuminant,Artificial intelligence,High dynamic range,Visual appearance
Journal
Volume
Issue
ISSN
28
5
0730-0301
Citations 
PageRank 
References 
38
1.25
26
Authors
3
Name
Order
Citations
PageRank
Jean-françois Lalonde159037.69
Alexei A. Efros210301634.66
Narasimhan, S.G.32348169.35