Generalized Image Acquisition and Analysis

Measuring BRDFs of Immersed Materials

We investigate the effect of immersing real-world materials into media of different refractive indices. We show, that only some materials follow the Fresnel-governed behaviour. In reality, many materials exhibit unexpected effects such as stronger localized highlights or a significant increase in the glossy reflection due to microgeometry. In this paper, we propose a new measurement technique that allows for measuring the BRDFs of materials that are immersed into different media.


A Theory of Plenoptic Multiplexing

Ivo Ihrke, Gordon Wetzstein, Wolfgang Heidrich
In: Proceedings of CVPR 2010 (oral).


Multiplexing is a common technique for encoding highdimensional image data into a single, two-dimensional image. Examples of spatial multiplexing include Bayer patterns to capture color channels, and integral images to encode light fields. In the Fourier domain, optical heterodyning has been used to acquire light fields. In this paper, we develop a general theory of multiplexing the dimensions of the plenoptic function onto an image sensor. Our theory enables a principled comparison of plenoptic multiplexing schemes, including noise analysis, as well as the development of a generic reconstruction algorithm. The framework also aides in the identification and optimization of novel multiplexed imaging applications.
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title={{A theory of plenoptic multiplexing}},
author={Ihrke, I. and Wetzstein, G. and Heidrich, W.},
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