Research Projects

Our research covers computational imaging, optics, graph signal processing, computer algorithms and system design.

Time-Of-Flight Multispectral Imaging

Spectral imaging involves the sensing of a large amount of spatial information across a multitude of wavelengths. Conventional approaches rely on scanning techniques to construct a spectral data cube. Recently, compressive spectral imaging (CSI) has allowed to estimate spectral images with as few as a single coded snapshot. On a different front, Time-of-Flight (ToF) snapshot imaging has gained considerable attention, due to its accuracy and speed. To date, however, these imaging modalities (CSI...

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Compressive Spectral Imaging

Recent research developed in the area try to focus in extends the concept of CASSI to a system admitting multiple shot measurements which leads not only to higher quality of reconstruction, but also to spectrally selective imaging when the sequence of code aperture patterns is optimized. The aperture code optimization problem is shown to be analogous to the optimization of a constrained, multichannel filter bank. The optimal code apertures allow the decomposition of the CASSI measurements into...

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Computational Lithography

Optical lithography has been instrumental in the shrinking size of semiconductor devices and integrated circuits (ICs) that we see today. Optical lithography – the technology of patterning – enables intricate circuits to be created in wafers at dimensions smaller than the light wavelength used in the process. Optical lithography is relying more on resolution enhancement techniques (RETs), since their implementation does not require significant changes in fabrication infrastructure. Computational...

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Data Science on Graphs

We are studying structured data science or data in graphs. Graphs are fundamental in modeling connected and structured data. The applications are timely and numerous. Nodes of a graph may represent individuals in social networks, brain regions in neural networks, and transactions in financial networks. Our research addresses the fundamental concept of graph sampling where the underlying graph signals are observed in a reduced set of nodes carefully chosen so as to enable accurate reconstruction...

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Electronic Printing

Blue noise dithering – high frequency white noise with minimal energy at low frequencies – has had a profound impact on digital ink-jet and laser image printing because it represents an optimal distribution of black and white pixels for producing the illusion of a given shade of gray. The blue noise model, however, does not directly translated to printing multiple shades of gray by the placement of varying ink concentrations or various dot sizes. New device printer technologies allow for such...

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Nonlinear Signal Processing

Linear Filters today enjoy a rich theoretical framework based on the early and important contributions of Gauss (1795) on Least Squares, Wiener (1949) on optimal filtering, and Widrow (1970) on adaptive Filtering. Linear Filter theory has consistently provided the foundation upon which linear Filters are used in numerous practical applications as detailed in classic treatments. Nonlinear signal processing, however, offers significant advantages over traditional linear signal processing in...

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