We consider the problem of deliberately manipulating the direct and indirect light flowing through a time-varying, fully-general scene in order to simplify its visual analysis. Our approach rests on a crucial link between stereo geometry and light transport: while direct light always obeys the epipolar geometry of a projector-camera pair, indirect light overwhelmingly does not. We show that it is possible to turn this observation into an imaging method that analyzes light transport in real time in the optical domain, prior to acquisition. This yields three key abilities that we demonstrate in an experimental camera prototype: (1) producing a live indirect-only video stream for any scene, regardless of geometric or photometric complexity; (2) capturing images that make existing structured-light shape recovery algorithms robust to indirect transport; and (3) turning them into one-shot methods for dynamic 3D shape capture.

The incremental multi-parameter (IMP) algorithm is described. The algorithm may be used to analyse digitised data from an array of sensors in order to estimate parameters of incident signals. It makes use of the conventional beamformer as a key component of an iterative analysis of the data, yet is shown IO outperform alternative eigenvector-based high resolution estimators, such as MUSIC, by 10-12 dB when resolving uncorrelated signals.IMP is also shown to be capable of resolving perfectly correlated signals at signal to noise ratios lower than required by MUSIC to detect uncorrelated signals. This is achieved without the need for spatial smoothing, enabling analysis of data from non-linear arrays. Finally, results are given which illustrate the robust performance of IMP when rhe antenna calibration is in error.

No abstract

We consider the problem of deliberately manipulating the direct and indirect light flowing through a time-varying, general scene in order to simplify its visual analysis. Our approach rests on a crucial link between stereo geometry and light transport: while direct light always obeys the epipolar geometry of a projector-camera pair, indirect light overwhelmingly does not. We show that it is possible to turn this observation into an imaging method that analyzes light transport in real time in the optical domain, prior to acquisition. This yields three key abilities that we demonstrate in an experimental camera prototype: (1) producing a live indirect-only video stream for any scene, regardless of geometric or photometric complexity; (2) capturing images that make existing structured-light shape recovery algorithms robust to indirect transport; and (3) turning them into one-shot methods for dynamic 3D shape capture.

No abstract