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Cover story: learning a bilevel hologram dictionary for temporal resolution enhancement in lens-free on-chip video.

Publication(s)

"Dictionary-based phase retrieval for space-time super resolution using lens-free on-chip holographic video"
Zihao Wang, Qiqin Dai, Donghun Ryu, Kuan He, Roarke Horstmeyer, Aggelos Katsaggelos, Oliver S Cossairt
OSA Imaging and Applied Congress, Computational Optical Sensing and Imaging (COSI), June 2017
[PDF]

"4D Tracking of Biological Samples using Lens-free On-chip In-line Holography"
Zihao Wang, Donghun Ryu, Kuan He, Oliver Cossairt, Aggelos K Katsaggelos
OSA Digital Holography and Three-Dimensional Imaging, May 2017
[PDF]

Images

A protozoa gallery for building a holographic dictionary for phase retrieval

Setup and phase retrieval


The left panel of this image presents our lens-free on-chip imaging setup. On the right, 5 types of protozoa along with the phase retrieval results are presented.

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Phase retrieval algorithm


Our "shrink-wrap" phase retrieval algorithm can iteratively recover phase information by gradually estimating the "support" (shape) of the object.

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Training a bilevel holographic dictionary


By training a bilevel holographic dictionary, we are capable of recovering high resolution holograms from subsampled holograms. Results show that our subsampled holograms allow imaging at an enhanced frame rate.

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Testing results


Our testing results show an improved performance over bicubic interpolation.

Visualizations

Digital refocusing from a holographic snapshot of Paramecium.

By applying the aforementioned phase retrieval method, we are capable of recovering the phase information from the hologram captures.

 

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    1 Comment

    1. Φθηνά καράβια
      July 15, 2017

      Very nice article, just what I wanted to find.

      Reply

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