Generalized Image Acquisition and Analysis

Three-Dimensional Kaleidoscopic Imaging

Three-dimensional kaleidoscopic imaging, a promising alternative for recording multi-view imagery. The main limitation of multi-view reconstruction techniques is the limited number of views that are available from multi-camera systems, especially for dynamic scenes. Our new system is based on imaging an object inside a kaleidoscopic mirror system. We show that this approach can generate a large number of high-quality views well distributed over the hemisphere surrounding the object in a single shot. In comparison to existing multi-view systems, our method offers a number of advantages: it is possible to operate with a single camera, the individual views are perfectly synchronized, and they have the same radiometric and colorimetric properties. We describe the setup both theoretically, and provide methods for a practical implementation. Enabling interfacing to standard multi-view algorithms for further processing is an important goal of our techniques.

Projects

From Capture to Simulation - Connecting Forward and Inverse Problems in Fluids

James Gregson, Ivo Ihrke, Nils Thuerey, Wolfgang Heidrich
SIGGRAPH 2014



Abstract

We explore the connection between fluid capture, simulation and proximal methods, a class of algorithms commonly used for inverse problems in image processing and computer vision. Our key finding is that the proximal operator constraining fluid velocities to be divergence-free is directly equivalent to the pressure-projection methods commonly used in incompressible flow solvers. This observation lets us treat the inverse problem of fluid tracking as a constrained flow problem all while working in an efficient, modular framework. In addition it lets us tightly couple fluid simulation into flow tracking, providing a global prior that significantly increases tracking accuracy and temporal coherence as compared to previous techniques. We demonstrate how we can use these improved results for a variety of applications, such as re-simulation, detail enhancement, and domain modification. We furthermore give an outlook of the applications beyond fluid tracking that our proximal operator framework could enable by exploring the connection of deblurring and fluid guiding.
Project Page Video

Bibtex

@article{Gregson:14,
author = {James Gregson and Ivo Ihrke and Nils Thuerey and Wolfgang Heidrich},
title = {From Capture to Simulation - Connecting Forward and Inverse Problems in Fluids},
journal = {ACM Trans. on Graphics (SIGGRAPH'14)},
volume = 33, number = 4, year = 2014,
pages = {xx--yy},
}
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