Generalized Image Acquisition and Analysis

Eikonal Rendering: Efficient Light Transport in Refractive Objects

We present a new method for real-time rendering of sophisticated lighting effects in and around refractive objects. It enables us to realistically display refractive objects with complex material properties, such as arbitrarily varying refraction index, inhomogeneous attenuation, as well as spatially-varying anisotropic scattering and reflectance properties. User-controlled changes of lighting positions only require a few seconds of update time. Our method is based on a set of ordinary differential equations derived from the eikonal equation, the main postulate of geometric optics. This set of equations allows for fast casting of bent light rays with the complexity of a particle tracer. Based on this concept, we also propose an efficient light propagation technique using adaptive wavefront tracing. Efficient GPU implementations for our algorithmic concepts enable us to render visual effects that were previously not reproducible in this combination in real-time.

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On Plenoptic Multiplexing and Reconstruction

Gordon Wetzstein, Ivo Ihrke, Wolfgang Heidrich
In: International Journal of Computer Vision (IJCV).



Abstract

Photography has been striving to capture an ever increasing amount of visual information in a single image. Digital sensors, however, are limited to recording a small subset of the desired information at each pixel. A common approach to overcoming the limitations of sensing hardware is the optical multiplexing of high-dimensional data into a photograph. While this is a well-studied topic for imaging with color filter arrays, we develop a mathematical framework that generalizes multiplexed imaging to all dimensions of the plenoptic function. This framework unifies a wide variety of existing approaches to analyze and reconstruct multiplexed data in either the spatial or the frequency domain. We demonstrate many practical applications of our framework including high-quality light field reconstruction, the first comparative noise analysis of light field attenuation masks, and an analysis of aliasing in multiplexing applications.
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Bibtex

@article{Wetzstein:PlenopticMultiplexing:2012,
title={{On Plenoptic Multiplexing and Reconstruction}},
author={Gordon Wetzstein and Ivo Ihrke and Wolfgang Heidrich},
year={2013},
volume = 101,
number = 2,
year = {2013},
pages = {384--400},
}
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