Frequency analysis and sheared reconstruction for rendering motion blur
Abstract
Motion blur is crucial for high-quality rendering, but is also very expensive. Our first contribution is a frequency analysis of motion-blurred scenes, including moving objects, specular reflections, and shadows. We show that motion induces a shear in the frequency domain, and that the spectrum of moving scenes can be approximated by a wedge. This allows us to compute adaptive space-time sampling rates, to accelerate rendering. For uniform velocities and standard axis-aligned reconstruction, we show that the product of spatial and temporal bandlimits or sampling rates is constant, independent of velocity. Our second contribution is a novel sheared reconstruction filter that is aligned to the first-order direction of motion and enables even lower sampling rates. We present a rendering algorithm that computes a sheared reconstruction filter per pixel, without any intermediate Fourier representation. This often permits synthesis of motion-blurred images with far fewer rendering samples than standard techniques require.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 27, 2009
- Source ID
- 10.1145/1531326.1531399
Entities
People
- Frédo Durand
- Kevin Egan
- Nicolas Holzschuch
- Ravi Ramamoorthi
- Yu-ting Tseng
Organizations
- Columbia University
- Institut National de Recherche en Informatique et en Automatique
- Massachusetts Institute of Technology
- National Science Foundation
- Office of Naval Research
- University of California, Berkeley