Webcam Clip Art: Appearance and Illuminant Transfer from Time-lapse Sequences
Jean-François Lalonde, Alexei A. Efros, Srinivasa G. Narasimhan
ACM Transactions on Graphics (SIGGRAPH Asia 2009) (2009)
teaser

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 of over 1300 sequences containing over 1.2 million images, 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.

Jean-François Lalonde, Alexei A. Efros, Srinivasa G. Narasimhan (2009). Webcam Clip Art: Appearance and Illuminant Transfer from Time-lapse Sequences . ACM Transactions on Graphics (SIGGRAPH Asia 2009), 28(5).

@article{ Lalonde:2009:Webcamclipart,
author = "Jean-Fran\c{c}ois Lalonde and Alexei A. Efros and Srinivasa G. Narasimhan",
title = "Webcam Clip Art: Appearance and Illuminant Transfer from Time-lapse Sequences ",
year = "2009",
journal = "ACM Transactions on Graphics (SIGGRAPH Asia 2009)",
volume = "28",
number = "5",
links = "http://graphics.cs.cmu.edu/projects/webcamclipart/ ",
}